If you want an issue fixed, you have to play the semantic games. It's not my fault you don't know what you are doing.
A stumble at steady speed is not a surge.
I sure hope you don't give advice to people...
Could you please explain how and where your indicators were installed. electrically? I mean, did you splice wires or jump connections?
I am willing to bet that this is two different issues.
Indicator misbehaves on a completely stock system, running for minutes? OEM system flaw- most likely...
I am going to posit that your bike DOES NOT have a surge in the midrange, but actually has a flat spot.
The FTR has a flat spot between 3000 and 5500 rpm...
Rule of thumb....
"If it started before what I did, but it doesn't start now, what I did is the issue..."
That being said... a lot of what you say makes me think the battery voltage is low.
I would buy another Indian, for sure.
I am getting old... so the cruiser market looks attractive.
What a lot of people on here complain about Indian versus HD versus Japanese is actually what I like.
Indian, from Polaris, from what it seems, is an American motorcycle with some European...
I've had my bike at max lean hundreds of times on track days... on the tires and springs that came on the bike... I was 260 at the time.
Max lean is 43 degrees
https://www.indianmotorcycle.com/en-ca/ftr-motorcycles/ftr-r-carbon/specs/
at max lean, if you go over any sizeable bump or "whoop"...