I don't think it is unreasonable to want to know where the R is headed. Three months is a long time with no plan and very little communication. If he'd said, at any point, that he wanted a D, I wouldn't reach out, but that doesn't seem to be the case.
But, I think Lisa has a good point. You saw him a few weeks ago, and he didn't seem interested in working on the R at that time. If you reach out now, will you push him into saying he's done? (Although personally, sometimes I wonder whether or not I'd really want to be with my H if merely asking for a status update pushes him that far away.) Or, as Lisa said, do you have a need for closure that outweighs that risk?
If you reach out, I would give a clear reason for seeking out the conversation. You could use the original "three month check-in" agreement as a starting off point, but are there any practical reasons you could give for why the conversation needs to happen soon? Maybe that will make it seem less emotionally involved for your avoidant H.
I feel for you. My H is also extremely avoidant. I have initiated most of the contact during our S and he seems fine with that. He told me recently that he feels the least anxious right after we talk -- and yet, he will almost never pick up the phone to call me. It's bizarre.
