There’s so many problems that it’s difficult to know where to start.
Towers
The towers were horrible. I basically couldn’t get near enough to do any damage, or even to see the tower itself. I usually ended up standing kinda nearby and waiting for those with a deathwish/hacks/divine pet to TP and take it down. Please, stop designing so tough content, it merely drives players to leech and/or hack.
Length
Making the entire thing take so long to fight and placing the second one at the end of a realm led to the unedifying sight of experienced (usually) players screeching at new (usually) players: “don’t kill lich you [redacted]”. It also gave a green light for organised groups and/or notifiers to wait out the TP cooldown, instead of the event rewarding those who had worked to spawn it. Please, stop designing events that take so long to complete (hello Dwarf Miner). It overly rewards leeching/notifying.
Rare UTs
Having the keysword be some rare item wasn’t fun (~250 it took me to get one). A fun thing would’ve been to hand it out to most everyone, for us all to spend the weekend running around shooting keys like loons. But making it low % simply pushes players into notifier use, which isn’t good. Scroogy drop rates aren’t fun.
I got one Tablet in those ~250 so it was hardly throwing out other UTs. I hesitate to say that’s good or bad, as I think the whole event UT thing needs rethinking but that’s for another topic. Fair to say it wasn’t broken.
Portals
The spam of portals felt bizarre, for it to throw out for example four Nests - what’s the point. One of each perhaps would’ve been better (like Craig/Court does) as people seemed disappointed when there was no Thicket. Maybe I’m non-typical here but I prefer dungeons from the bosses anyway, and hardly joined any, wanting to focus on the keysword farming.
Improved vs first Keyper
One positive was the improvements vs the first Keyper event, as Keyper boss v2.0 was a bit more enjoyable to fight, though agree with OP the confuse is nasty, and the quiet spam (instead of silence) is as always overly harsh to lower pet players. The new shard tokens, to reassure that you have done sb dmg, and work towards the keyring UT, was the saviour of the event, I would have ignored it completely had this not existed. But please get these obvious things in from the start when designing future events.