Hmm, falling back to sRGB is really the best option as that seems to be the most widely used option in various softwares, so less room for confusion.
Instead of having “sRGB” in parenthesis in the UI, what about an “on-hover” tip that says sRGB will be used if no embedded profile is found? Or even just a note in the “help” section? and then remove the essentially duplicate other “embedded” option?
Some softwares provide an additional option to use some other user-selected profile (other than sRGB) for images without embedded profiles. But this option only helps people with a very specific workflow where something other than sRGB is the most common profile that will be assigned for images without embedded profiles (for example people loading scans that don’t have an embedded profile, and to which a custom profile needs to be assigned).
So this additional option could be provided as a user option in PhotoFlow, but maybe only if users actually start to ask for such an option?