I think there are other problems that could arise if they changed it to a CT-style loot lockout - I don't know if I'd consider those problems to be worse than the problems with the current system, but they would definitely exist.

What I can't see a problem with would be allowing people unlimited access to a version of each Coil turn that has no lockout, but also no loot, period. While that wouldn't solve the problem of a Coil static needing to consist of exactly eight players (no more, no less), it would allow people to play with their friends outside of a static instead of needing to essentially just leave them behind, and it would allow an experienced static group to teach fights to other friends or FC members without compromising the progression of their static party - and since a player who knows and is experienced with a fight has a much easier time finding a proper static party of their own in the first place, it would increase the pool of players who are actually participating in Coil content, which benefits the entire game, and the entire community.

It really sucks to have to tell your friends "No, I can't play with you in any place that actually matters in this game."