uncle told him if we can work out our difference before the first of the month there is no problem with him not staying there. Is that a hint to try for the next few weeks?
Don't read into things. Maybe uncle just doesn't want to have a permanent house guest.
I just need to know what to do.
Stick with the major plan overall despite any little things you may be tempted to analyze: GAL, detach, PMA, treat H like a good friend instead of as a H.
can I allow a friendship with H and OW.
It's not up to you. H's going to do what he wants, and if you voice an opinion against it, he'll probably do it all the more. Ever read Dr. Hartley's Plan B? It's about a no nonsense approach, telling the WAS that "if the A is to continue then it's no more LBS! It's one or the other, buddy, make your choice now" and sometimes that works... but sometimes it doesn't. So, maybe a way to get H to realize life without you is for him not to experience you as often. That's part of what happens when you detach and GAL, so that H starts to think about you and what you may be up to, and by absence of details lets their imagination fill in, and imaginations can do some pretty wild stuff.
But if and when you reconcile, then things change where there must be No Contact between the WAS and the OP.
In the meantime, if it's the OP he wants, nothing will stop him. But let reality overcome their relationship when they're faced with it, and it may hasten their demise. Which reminds me, I give Charles and Camilla two years max.