I think you can use Aurora instead, which is available from F-Droid, and provides anonymous login to get Play apps.
See: Anyone Successfully Run WayDroid on Librem 5? - #114 by netnut404
Check out Kyle’s post on that, if you haven’t already: New Post: Snitching on Phones That Snitch on You
You can test it with some innocuous Android app in Waydroid and let us know. 
Another option for blocking trackers is to subscribe to a VPN service that actually incorporates tracker- and ad-blocking DNS filters, such as AirVPN, which is the one I use. Its Wireguard protocol works great on the Librem 5. (Although Opensnitch has the advantage of being able to actually show you what is being blocked. The VPN service may not do that, but they generally use the well-known tracker/ad-blocking lists you can find online or via uBlock Origin, etc.)