the burger attack only deals damage if you cure yourself of hunger

It’s not about the burger attack though. You can hit it with shock and forget and simply not deal with it at all. Still, since now in Royal you have to kill all the robots in two turns, it’s impossible. Without the all out attacks, you hit the weaknesses but you don’t deal enough damage to kill them. At least not in two turns before they go away and the fight resets.

The countdown happens in real time so part of the problem might be your APM/not skipping through dialogue when possible. If you’re getting close to the end that might actually be your only problem, because it’s such a long fight that even being able to shave a second off each of your actions by getting more familiar with the menu and not switching personas much could save you a couple minutes in the end. If you’re using buffs properly and still not getting to the end you might just need to grind levels more. You should be able to one or two-shot the first wave of workers after a matarukaja

Bring Haru to the fight and make sure Joker has a Persona with some kind of Mapsio skills, the last wave is weak to Psio. Abuse Weaknesses and baton passes, don't bother healing, each turn counts. This is the only boss that gave me trouble, I dunno what Atlus was thinking when they buffed Okumura

Yeah, I beat it abusing Baton Pass, but jesus... It was the hardest by far.

I can only assume it was because most people would be able to beat him with a lot of time left, so they wanted to make it actually challenging Idk though

Still though, I think they made it way to hard for a mandatory storyline boss fight. I personally consider myself to be a pretty great at p5 combat (not trying to boast or anything I just sunk 500 hours into the first game because I'm a loser) and I even had a really hard time with it. Granted, I was playing on hard and I ran past a decent amount of enemies to the new story stuff (mostly Kasumire of course) more quickly, but still, to a brand new player (which I know there are a LOT thanks to Royal) who is just beginning to get the hang of the menus, weaknesses, technicals, and battle mechanics in general, it was likely a terrible time and a real morale dampener for them. I honestly think that they should change specifically the final wave with the big green bots back to how it was in p5 where you just had to kill them, but maybe spice it up a bit if they wanted.

That One Level needs That One Boss. Okumura's Palace sucks so of course it's boss is going too as well. It's like Lost Izalith and the Bed of Chaos.

I'd like to add I actually like the changes to this boss fight. He was initially really easy to beat and really boring after all. Positive change to royal, especially with cognitive Haru. Even if it made me want to pull my hair out the first time around.