Very similar to my setup. 32gb ram, gtx 1080, ssd, 1630 pictures about half 12mp and half 42mp.
The last part of reconstruction, where it reads in the console part x/500, the last 20 or so took longer than the first 400. It used about 80GB of memory on those last 20 parts even though they where only like 20-50 vertices. After a few restarts I just let it run making sure my Virtual Memory was assigned to the fastest drive, as this was the bottle neck in this run. I tried to allocate my cache to my second fastest SSD and VM to the fastest.
I don’t have any expertise on model editing and recombining meshes is beyond my skills, so Gotz or Jonathan are more qualified here.
I should mention that it took 1-2 weeks of trying to get the settings right and restarting to get to the 48 hr run. If I had just let it run the first time (it just seemed sooo slow), I could have been done much sooner. You have to consider the dead line. Is testing a new work flow that could save time really going to save you time after a few restarts and mistakes?