I cannot see that you could have any problem. The display of "Computer #1 of X" only occurs when you use more than one dive computer simultaneously during a specific dive. If you do this and download the same dive from both dive computers then you can access both dive profiles independently. If you switch over to the Sherwood and only download from the Sherwood, Subsurface will show the dive computer correctly . All your old dives using the Cressi will also show up correctly. One thing you may consider is to check if a download button exists for the Cressi on your download screen. If you do no use the Cressi any more you could consider removing the Cressi button by selecting Settings -> General settings -> Forget dive computer.
Kind regards,
willem
Since I've read the Subsurface-mobile displays computer #1 of X, what will happen when I switch over?