Updating my own experience.
I had to remove TOOL to get my game to even allow live-mode play.. so.. no cool builds.
However, I did figure out what I had to get rid of, UI extensions mod - one of a handful that I honestly don't wanna play without, bc who has time to actually explore new gameplay when all you are doing is having sims eat, pee, shower, and sleep for ridiculous amounts of in-game time...
So I did create a new save after removing this mod, and while the UI didn't let me select anything, suddenly it popped up with both "quests." I did complete BOTH tasks (I used a highly skilled sim that I have been playing that I imported from the gallery saves I had before I went and messed with my mods folder) without leaving the lot or saving and exiting. I chose a lot with access to wild snapdragons and used the NPC sims that welcome you to the 'hood to ask about ambrosia. Only needed a computer, séance table, and then obvi the grimophone after that unlocked..
Oh, and if you play with custom recipes, make sure you use one of the EA recipes.. I ended up using blacked bass after two other attempts didn't work - I do also have multiple pie menu mods.
So, it IS possible (so far) to do the event without TOOL and IU extensions... if the modders fix it, I will try it again. I have several Patreon subscriptions, but the UI creator isn't one of them, so I cannot give feedback there. I honestly think there is a massive glitch on EAs side, as people with no mods are still experiencing issues if they leave the lot or get out of the game without completing a quest.
Another note, I DID use cheats via MCCC and shift-click several times during game play, and it did not affect the event at all. I wasn't allowed to use the freerealestate cheat, however. so just picked a tiny little house with a yard.. bc, gardening.