Also been trying out Obtainium for a while on Calyx and now Graphene. Experienced rate limiting for the first time yesterday which was frustrating.

I will say those that have been promoting Obtainium over apps stores like F-droid aren't mentioning some of the issues. F-droid is far from perfect but using RSS feeds or Obtainium is not viable for novice users yet IMO. I like Obtainium btw and I'm sticking with it for now. Its a new project and I like the direction.