We've been building the RISC-V port from a combination of Fedora and CentOS Stream sources--the same as the core operating system--since early 2024.
A lot of RISC-V support was already in F40 (which EL10 is cut from), so the rest was largely backporting and integrating into RHEL, which again, we've been tracking since CentOS Stream 10 was branched from Fedora last year.
We do love collaborating with our upstreams--I myself recruit folks into Fedora and CentOS whenever I can, in addition to Rocky.
It's more than words and sponsorship--I really do mean it when I say I want to empower the Enterprise Linux community, and I'm thrilled that Rocky is at a point where we're able to do so.