5 weeks is just too soon, it is great that they have no fights but humping can be also dangerous. I would separate them for 3 more weeks to avoid injures. In my experience i had one newly neutered boy (9 weeks ago) added to a bonded group of neutered young rabbits (interesting that one of them was neutered same day as this new one but he calmed down earlier, around week 7) and first day went well then he started humping everybody, looked like he befriended one which is super submissive and calm, but he kept humping him as well. I didn't want any serious conflicts if others will start going back after him or if he'll get his genitalia damaged while humping their heads and removed him from group for another month. This is individual, but I've got a few young rabbits neutered this year and can tell, 8 weeks would be minimum to keep them separately, it was 3 months in two cases, and I find that if you have them completely separated so they can't see or smell another males they become calmer sooner, they are much more relaxed then as well and you can use that time for bonding with them and training them, it will help you to understand them better individually.
As for your rabbits were previously bonded in your situation they were still babies when you've got them and it was just baby bond because all babies get along until they are 3,5-5 months, so they were not bonded this simply doesn't count like bond at all.
So I would separate them for a few more weeks and would keep them individually so they don't see each other, also I would restrict free roaming for Finn, I would limit their territories for that period of time so they can forget each other and you can start bonding in a neutral territory where they both were never before, also with their smells removed with white 5% vinegar from all things, toys etc.
But if your Finn is super submissive providing hiding places could work as well if you are 100% sure that he will not lose his patience when you are not supervising, it can lead to serious damages so honestly I wouldn't risk. I would just wait 3 more weeks it's not too long, sometimes can take a bit longer.
I mean, why risk if it's just a few more weeks?
Good luck and please keep us updated