How to prevent systemless Xposed Framework from crashing Play Store?
The developer of GravityBox Xposed modules, C3C0, suggested to use official and original Xposed Framework (flashes system partition and breaks  Safety Net). They confirmed it working alongside Play Store, but on Android 8.0 though.
Alternatively, one can try Aurora  Store from F-Droid, as an alternative to Play Store and as an interim solution. It fetches apps' updates and new apps directly from Play Store. It also provides sufficient information regarding the app to be installed, such as What's new, permissions, and so on.