I feel like I ought to clarify the title of this post. At first look on line, I didn’t realize that the gauge of LaBella 760 strings were identified by the two-letter suffix FM, FL, FX, so I was going to ask if there was a different type of LaBella flat (like the LTFs) that still sounded like the 760 FMs. I had already started the thread when I figured out the two-letter suffix was the gauge, so 760FL or FX should obviously sound like 760FMs.
There's also the LaBella 760FS set, which is standard 45-105 gauge. Had them on for a while and felt normal stiff for flatwounds. Fender and Dunlop flats are considerably more flexible but also have a different tone character that you may not like.