I think that's a shadow rd, meaning it will not necessarily be compatible with the road pull ratios. So your brifters suggestion might not work either.
I tried the friction shifter route but couldn't get it to work or find much online. Think the rear mech is not shadow but would replace if it fixed the problem. Thanks for your input.
Run the bar end shifters as friction shifters?
I think that's a shadow rd, meaning it will not necessarily be compatible with the road pull ratios. So your brifters suggestion might not work either.