@catx3
Hey that's a pretty good explanation. I hadn't even considered the possibility that, from Baku's point of view, there could be another 25 with Lalo. It just seems so counter-intuitive to think that there could be two same cards in the game, but Baku does not have the luxury to make that assumption so he has to factor it in his plan too.
Lalo having 25 along with 47 does makes the alternative of not telling the law much more dangerous because even if Baku does successfully destroy 47 using his 45, he has no way of destroying Lalo's 25 without destroying his own. Also, as you pointed out, even if they clash it still gets wasted and Baku loses. So yeah Baku had to make sure that his 25 does not clash with either of Lalo's (potential) ace cards, and the best way of doing that is to tell Lalo the law to make him play his ace cards early.
There's just one hitch in the plan that if Lalo had a 25 and played it in the 4th round, it could potentially destroy Baku's 25. There are two suits (hearts and clubs) remaining which could be used to make the straight flush to 7 and even if Fukurou makes Lalo's 25 using one of them in the 4th round, it still leaves the other for Hal to use in the fifth. But the problem is Hal used the 4 of hearts to make full house for 26 in the fourth round. So, if Fukurou makes straight flush to 7 using hearts, it could potentially trigger a calamity (I don't know if overlapping hands trigger a calamity if a hand is invalid) and if he used clubs, it would destroy Baku's 25.
Other than that your theory also explains why Baku didn't fold in the third round. Baku's plan involved folding in the 4th round, so he had to know if folding triggers the calamity. So, suppose Baku folds in the third round and the calamity triggers (I also don't know if overlapping hands still trigger a calamity if a player folds,does it?), then Baku wouldn't know if the calamity triggered due to folding or due to overlapping hands. So, I guess calling was better because there was a high chance that overlapping hands did trigger the calamity so the confirmation would be nice for the plan.
Your points about the sound and Hal do make sense because as Yakou said, Manabe and Shion were the only one who could intervene in the gamble so they had to be close to Fukurou and Hal to make sure that everything goes well. But how did Baku know that the top room was the announcing room? I think Baku and Lalo thought that the announcement room was the one above them in ch429. But yeah even if it was a pretty big gamble( soundproof rooms,3f or 2F, etc.) it had somewhat reasonable odds.
But tbh I would really like some sort of explanation or reason from the author for Baku believing that Hal would regain his memories in the next arc.
Again, thanks for the explanation