Upload & Sell: Off
I'm looking for something better. Plus, I don't want to waste an external editor preset on the same tool
I'm not sure how much better it can be than creating an External Editing Preset of 8 bit and 16 bit. I also don't understand the worry about "wasting" a preset. How many do you have now?
Have you noticed that if you open up the Copy File Options in the "Edit Photo with" dialog, that it stays open from photo to photo and from session to session, in effect giving you the pop-up you are apparently looking for?
All the External Editing presets automatically create an intermediate file and I know that bothers some people. Is that the issue?
How about handling it on the PS side? Just always bring the file into PS in 16-bit and set up a short-cut key to switch the mode to 8-bit.