R has been around a long time, but what matters is how it matches your needs. It is horrible for higher carb meals, but great for those that do low carb/ higher fat-protein.
I have been pumping for over 25 years. No problems with scar tissue. Have you tried different sets? Some think the needle sets (rather than cannula) work better, and may not scar. I use Quick sets, rotating sites between stomach and back/hips.
I went from using NPH/Reg injections, to Reg in pump (now novolog), so no experience with the long acting insulins. I would consider Tresiba if I stopped pumping, but have heard some report burning after injection. I used Lantus, Levemir only during pump outage.
Why did you take lower dose of Tresiba than your basal? You could try higher dose.
That’s a personal decision. But I know my next pump will not be medtronics, even though that’s all I’ve had.
I think someone has posted here about how to get omnipod covered by UHC.