I just run into this problem all the time as I use the snapshot function a lot.
When I get into the Metadata (IPTC) template and click on the snapshot button there are a maximum of 14 snapshots visible, but the box does not allow scrolling up or down to other snapshots but the little arrow needs to be clicked to get to those other snapshots.
Interestingly when you choose to save a snapshot you get a nice scrollable window to choose one of the snapshots.
Could the scrollable function also be implemented on the window when clicking on the snapshot button to choose the needed snapshot? It would speed up the process a lot!
(PM6 Running on Windows 10)
I think you can hit a letter as a shortcut to the snapshots that start with that letter, but it doesn't look like they scroll on either OS. I'm on macOS and added 15 just to check.