Didn't even need to test it out in the mod. All the <BSL events should come after <BOA there, not just the first time. So move 'em between <BOA and <END and it should work.
I see the <MOV0010:0031 got removed.
Also, I'd recommend the use of <DNA0309 (I think?) OR the use of <PRI instead of <KEY, after a phase is defeated - Butes tend to remain after Heavy Press's defeat, and PRI freezes the game until KEY or END is used.
I had the <MOV removed because I was trying to figure out how to work the script properly. I've added it back in so I'll also need to work to fill out all the other details in the fight. On the other hand, I'm proud of myself for successfully scripting the Taboo-Ga fight (uses Core's A.I) so I'll continue working on that.