Hoo boy! Interesting time ahead for you!
I think it was a good plan to stop any further bonding attempts with the 7mth old and your pair for now. Definitely wait another month at least. As for how you go about bonding the 5, I really dont have advice on best way to do that but just some thoughts on possible challenges. I did want to firstly advise not to split your bonded pair at all unless they begin to fight with one another and cannot be trusted together anymore.
Some challenges at the moment might be that there are still 2 intact rabbit in the house. So any attempts of bonding with the desexed rabbits could be negatively influenced by that due to their smell. If you have the space, you could set them up in opposite ends of the house. Or, as you said, wait until all are desexed and the hormones have depleted.
I suppose I would attempt the pair and boy again in a month and if that isnt looking promising after a few weeks, the older single girl should be recovered enough to try her with 7-8mth old boy. If successful, you’d have the youngest boy to try to introduce to either M-F pair.
I do recall a story from years ago about how a woman was able to bond a big group. She would have the bonded rabbits on one side of a fence and bring in a new rabbit to live on the other side for 2 weeks. It seemed after that time the group would accept the new rabbit. This may be because it was already a large group and the dynamic becomes different.
You could try something like that, introducing a each new rabbit to your existing pair, one at a time. My only concern with that is – what if you end up with 4 bonded and one that it doesnt work for? Do you get another rabbit for that single one?…. 🙃