" initial data collected on subsequent site visits so separate forms don't work"
- You would push all of that out in Collector also. Just relate the forms back to the locations and you can see them all in the attribute table. As soon as a form is sent it would show in Collector.
The Inbox will get crowed in my opinion. Plus it gives you no info on how to find the location.
For us the big one was people picking the wrong location from the list. This is hard to find because no spatial info (now you can make a repeat a FC but before table only - you made it spatial right?). With separate forms we see right away they went to the wrong spot. Plus editor tracking and all that.
Up to you just sharing lessons learned.