-
The one I have is 11 speed, but you can just trim the stop back on an 7/8 speed one to get more throw. The issue with that on a thumby is the lever ends up in a strange place when in the big ring. If that’s not enough you can build up the inside of the grove the cable sits in to get more pull. I think Russ over on PathLessPedaled has a few vids on YouTube showing what you need to do.
On my Sequoia I’m tempted to just get a stupidly small narrow wide to have as a bailout gear on the inside and just manually change between the two (probably 4 or 5 times a year)
Sounds like a good plan. On the 10 speed friction shifting, I have 11 speed friction with an MS barend and it works great. Dropping down from the big cog is weird though. You just touch the lever and it drops. The rest are muscle memory ;)