Hey look I am offering unsolicited advice... My two cents. If you can handle the recovery the 4 days is cool. There are a lot of weeks where I do all my training in 3 days. For me with travel it is what I can get when I can get it. Second open mat is always challenging. I try and have a plan and at least 2 committed partners before I show up. Otherwise it can end up being not as productive as I want.
Good luck with the sleep issue. That would be really hard for me.
What we think, or what we know, or what we believe, is in the end, of little consequence. The only thing of consequence is what we do. -John Ruskin