Thanks for the feedback! Glad you're finding Public Package Manager (and our Linux binaries) useful!
We do have arm64 binaries on our list of requested binary distributions, but it's not currently on our short term roadmap. Since we provide comprehensive binary support for the entirety of CRAN, not just on the latest version of R but also for the past four R releases, every distribution / platform variant we support adds over 100,000 binaries that have to be built and maintained. While we'd love to provide binaries for every requested environment, we do need to prioritize our limited resources where most needed.
Requests like this are appreciated and encouraged, as it does help us recognize the demand and prioritize accordingly. In that vein, can you give us a little more detail about how you use these binaries, and what arm64 Linux distribution(s) are most important to you?