I wanted to come back with an update to see if anyone could offer more advise. I feel like things are going really well, I'm just not sure what to do to really seal their bond and make it more solid if that makes sense.
Over the weekend, I put them in a 4x4 pen, with a litter box, toys, water, etc. and just watched how they did. After about 3-4 hours in their they did great, no fighting or aggression at all. But...we're still seeing chasing and mounting from Gizmo. Nova has gotten savvy to Gizmo and runs away, or when Gizmo does manage to mount her she knows how to get out of it, she doesn't just sit there and take it like I know some rabbits will do, but she doesn't get aggressive either. She just hops or runs away, and if Gizmo tries again, she hops away again. In between that happening, Nova groomed Gizmo (still not seeing Gizmo groom Nova), Nova requests grooming from Gizmo but Gizmo doesn't comply. They eat together, they will flop down and just chill for a while (sometimes right next to each other, sometimes not so close).
Like I said, overall I feel like it's going well, and I think I'll continue to do bonding sessions in this now bigger space we have set up if that's the best way to continue for now? I'm also switching the rabbits out to each others cages every day so they get used to the scent of the other rabbit in their living space.
Because they did so well for such a long time, should I just put them in that 4x4 pen together anytime we're home with them to supervise, or should I move forward and try to have them in the same living arrangement permanently? Anything else I can do? Like I said I think things are going well and they seem to like each other, I just feel like I need to make that bond stronger, and hopefully the chasing/mounting will settle down?