Have you had a chance to try out StepSmash in the last week or two? Our StepSmash 1.13: Personal Challenges and more badges! release contained all of the fixes for syncing Health Connect that were found while figuring out why your Polar data wasn’t syncing in correctly.
If Polar is still syncing bad data we might be stuck, but if that Health Sync app is sending steps, distance, and heart rate data StepSmash should be able to work with it.