That's odd about Cyclemeter's GPS interpolation. When I used it in 2016-'17 Cyclemeter's GPS tracking was generally more accurate than Strava. When my phone lost GPS sync Strava would show a straight line until it resynced -- the straight line would cut across fences, through open prairie, etc. But Cyclemeter was smart enough to guesstimate the most likely route and was more accurate.

I might try a Cyclemeter subscription again in 2020. It offered some customization that I liked. It'd be useful for voice prompts during training sessions.