Seems editing posts isn't a thing, so update: I just finished my playthrough (112 hours) CorlainValez and the one single person I had seen elsewhere were correct, there's a single semi-missable item merchant directly before the final battle. It did have at least the unique armor from the faction vendor I lost, but it still didn't have everything, not even the final upgrade for one of the swords I used for most of the game (darkshard), nor the belt (tincture kit), so no clue where those are even from but they weren't there, along with Bellara's trinket humming curiosity, and her bow concentration. Yet there were companion trinket upgrades from epic to legendary despite that doing nothing for stats. All that being said, having this shop directly before the final battle is basically pointless in my opinion. I think a better option would have been a wisp which has it's inventory expand to include items after going to an area you can't return to if you missed it, and/or after you lose vendors during the story, especially since there's seemingly no way to get the decor or appearances (Like the crow mask AuramiteX mentioned) that were missed in any way. It also wouldn't annoy me as much if it weren't for the fact I ended up with a tooon of legendary gear I never wanted to use, but couldn't find the upgrades for some of the ones I did want to use.
A couple other suggestions that came to mind; Names of subareas on the map when you hover over beacons. More decor items would be nice. It also would be nice to be able to choose the color scheme of clothing/armor, I personally don't care for how many colors were used per outfit, the only ones I ended up using for appearances were the preorder bonus, deluxe, and the rebel armors.
And now that I've reached the ending, to add onto the "more companion/romance interactions" suggestion, I think the final romance scene is WILDLY out of place and should have occurred prior to the main story quest leading up to it. The timing is absolutely atrocious and immersion breaking seeing as the previous quest you suffer an unavoidable major loss, which your character thinks is actually 2 losses, plus finding out about a 3rd that's just been a mind game up until then. To go from that, going around talking to everyone while they're all upset, to Davrin's romance scene, was jarring to say the least. Maybe the other companion scenes fit the tone better, but I doubt it. I had the option to talk about how my Rook is the happiest she's been in a long time? After ALL that just happened? Davrin's just that good? Come on now lol, not to mention practically all interactions with your romance interest up until that point at are practically platonic aside from kissing maybe twice, it's such a leap at such a bad time it's insane.
And finally, unrelated to anything else I've brought up (I was reserving judgement until finishing the game), I just gotta throw it out there, the biggest thing that drew me to this series was the fact that your choices make major impacts, not only on the current game, but future ones too. Back when Veilguard was still Dreadwolf, I tailored a dragonage keep save to my personal canon save choices in anticipation of the game, and planned to eventually replay all 3 before 4 released. However, before I got through DA2, it was announced dragon age keep wasn't going to be implimented, with a lot of excuses about wanting to make sure the choices have a big impact and 4 taking place in a whole new region, but that the game would be respectful about it and not contradict any previous choices. I thought those excuses were valid, after all, there's a lot of choices at this point to try to sort out while making a sequel. Then I saw the inquisitor would be making an appearance, and only 3 choices would carry over, and that made me nervous, and turns out I was right to be. First of all, what was the point in even choosing those 3 choices. The romance choice doesn't get brought up whatsoever, I assume the only exception is if it was Solas (mine was Cullen). The other two had literally zero impact on anything in the game, or interactions with the inquisitor. I imagine if I chose opposite for those two, the only thing that would change is a line or two of dialoge and/or in a letter. So much for wanting to keep the choices impactful and meaningful. Secondly, destorying all southern regions "off screen" via a couple sentences and a couple letters is insane world descrution, and comes off as trying to reset the board so those previous choices can be wiped because everything burned to the ground anyways, which would completely defeat the purpose and meaning behind those entire games. So much for being respectful to worldstates. Third, despite being in a new region, there are more than a few references to either concepts, or even straight up characters, where a small choice could have been implimented, even just as an easter egg type thing. Instead those moments happened and I was rolling my eyes at what could have been. So much for a new setting that wouldn't have a place for previous choices to be included. Fourth, and probably in the grand scheme of things most importantly, everyone having their stings pulled throughout the entire series and boiling literally everything that's ever happened in anyone's history down to elven gods and some mysterious cult is, sorry, garbage. It feels like the biggest possible cop out to actually having any kind of depth to any lore except elven history, which is also watered down to a few table meetings and then barely talked about despite the worldviewshattering revolations, with the only exceptions being Harding and Bellara saying the same things about it but phrasing it differently repetitively. The worst part is, I can't even think of any way to possibly even salvage the wreckage this stuff made for future games without just pretending veilguard isn't canon and never playing another DA game that comes out, which, to be clear, isn't what I want. DA has been one of my absolute favorite series for well over a decade, and I did enjoy this game aside from the main story, but that's the most important piece for me overall. I almost wish the post credit scene was rook waking up in the back of a carriage being told, "You're finally awake", especially after what they did to Varric. I understand why it happened story wise, but it felt so disrespectful for such a long standing fan favorite to have been offed at the start of the game and turn out to be a hallucination the whole time towards the end. I thought he was just getting sidelined to avoid him interacting with any cameo characters and to focus more on the new companions. Plus Solas getting a redemption ending after that, that you have to put effort into unlocking, is even more disrespectful towards him in my opinion, but I'm also not on the Solas hype train so maybe that aspect is biased.
Anyways, I just wanted to rant because I just finished the game and I'm sad that I tried so hard to like it and put so many hours into it, just for it to slap me in the face for all the hours I sunk into it's predecessors. I don't expect anyone to read it or care lol. Though I will say one more time, golden nug please, that's the only way I'll ever sink that many hours into a playthrough of this game again, I can't bear to collect everything every single time with this lack of payoff and high chance of missing things.