Hello EA_Mako & thanks for the response.
I was already aware of the upcoming (now present) buffs at the time of posting.
I approve of moving the then-level-3 perks to level 2, as Ferro-Door will be heavily desired early in games as the increasingly popular Fuse's Knuckle Clusters & Mad Maggie's Riot Drill bombard Catalyst's shelter, & Resilient Veil would also be desired heavily for early rotations. Decreasing Dark Veil's deployment time was also needed, as I cannot count how many times I've placed the line of spikes only to be beamed before they can rise. Catalyst used to be the only controller who couldn't effectively make a door unavailable to an enemy with their Tactical, & it's nice that doors can be reinforced from afar. However, along with their aforementioned lack of synergy with Dark Veil (which is a problem concerning Dark Veil), I still have some quarrels with Piercing Spikes. In fact, my personal list of suggestions for Catalyst suggested increasing the height of Piercing Spikes' hitbox & making them reinforce doors they touch, both of which have now been implemented.
I love that Piercing Spikes finally reinforce doorways, but I'm sad to see Sole Piercer leave. Its replacement does 10 more damage per second & eases the problem of enemies leaving the spikes before taking a second tick of damage, but getting any damage at all with the size of Sole-Piercing spikes when used at a distance was already hard enough. Ferro-Frenzy spikes are even smaller than I thought they'd be after watching the gameplay trailer, & are also much easier to escape early without taking any damage due to the slower activation. It's only slightly helpful that the perk lets you place 1 more spike at a time because it doesn't grant +1 maximum charge, so 2 will cover roughly the same already-small area as 1, but leave you with nothing left to throw. It would be better if it either activated quickly, had the same size as regular spikes, or granted +1 maximum charge.
I've never picked Hidden Spikes, & that aversion has only been exacerbated by Piercing Spikes reinforcing doorways. Hidden Spikes shone when enemies opened a door to have spikes materialise under their feet. This would be unexpected because the orb would be hidden behind or beside an innocent-looking door, but that's no longer viable with ferrofluid on the door, which also deters enemies from passing through the doorway. Hidden Spikes have only become more situational & less viable with their automatic reinforcement. Due to how situational they are, I expected Hidden Spikes to be incorporated into Catalyst's base kit & replaced by another perk before I knew what the buffs would be. I now think a perk that implements the suggestions for Dark Veil would be a good candidate for that replacement.
Those are just my buff-related quarrels with Piercing Spikes.
By default, Catalyst should be able to have a maximum of 4 Piercing Spikes in existence to (1) match the maximum of 4 reinforced doorways & (2) facilitate owning space more similarly to other Controllers (except Rampart, whom I see as an Assault Legend). However, implementing the aforementioned Dark Veil suggestions would already let Catalyst hold that much space, so this wouldn't be needed as much.
You should also see a highlight (such as the one given by Hidden Spikes) in the shape of Piercing Spikes (much like Dark Veil), so you know how it'll manifest after throwing it. This is especially needed now that Piercing Spikes reinforce doorways, as you sometimes throw the central orb near a doorway only for it not to get reinforced because the spikes didn't go through it.
The central orb of Piercing Spikes should change colour from blue to red through walls (so it's still blue if you have line of sight to it) when they're activated, since simply rising a couple of inches (millimetres IRL) isn't noticeable from afar.