Okay I'm about to go super weenie here, but that's where I am mentally. You probably already know this, but per this paper, the FV3 is being retired as well when RRFS comes online: https://journals.ametsoc.org/downloadpdf/view/journals/bams/aop/BAMS-D-25-0323.1/BAMS-D-25-0323.1.pdf
The RRFS switched to MPAS for v2, which is (I believe) what we're watching slowly roll in. Supposedly, even v1 outperformed most high-res models, with some reflectively issues that have hopefully been resolved per that paper.
I'll stop now.