You can also create an account and just leave a note on the map (a message that other contributors to OSM see) mentioning your observations. It's a good option if editing the map is too overwhelming with all the different tags and how routing algorihms interpret them.

That's good advice. I updated the route in OSM and it now recommends a better path, but still not what I'd consider the safest/still not what Strava recommends. It seems like it prefers shorter distances with painted bike lanes over having a protected bike lane at all points of the journey. It'd be a neat option -- prefer protected lanes even at expense of more distance.