Let's try this:
Bad Batch generates buffs like no one's business.
If there isn't a B2 to dispel all buffs, 2xZA, 2xthe disk that gives +Off% on a buff, 4x the disk that gives +TM% on a buff.
You start out with high attack values for Tech and Echo b/c of ZA, and everyone ramps up Off% incredibly quickly. Each buff gives +2.5%TM per disk, which means +10% per buff. Between throwing buffs around, Hunter's TM swap, AoE Stun, and the CD reduction from Translation, this seems doable.
It's probably a little like Places of Power where you're trying to time the JKL mass assist for the end of a wave to get that opening stun, right? You'll want to to get Tech assisting to reduce cooldowns and always end a wave with someone near 100% TM so that they can kick off TM gain for the next wave allowing you to AoE stun again.
And, of course, if this doesn't work, you can try Imp Troopers with the same disk setup The combined offence ramp from disks + Emp's Trap has to be huge. The only thing I worry about is the lack of an AoE stun, but maybe their TM gain + Off will be enough.
Now, you can't guarantee that you'll have all those disks quickly enough to do this on your first pass, but you could have this disk setup by end of S5 and then come back and do 600 (or 540, really) on just one additional battle.