For whatever it's worth, my memory/motherboard does not seem to exhibit this issue. My XMP 2.0 values populated and booted without any fussing, and the tCR value is accurate.
MB: ASRock AB350M Pro4, BIOS v2.5 (AGESA 1.0.0.6)
Ram: Corsair LPX 2x8GB 3200MHz C16 (CMK16GX4M2C3200C16S)
Timings: 16-18-18-36-54-1 (tCAS-tRC-tRP-tRAS-tCS-tCR)
https://valid.x86.fr/te3x7z
A new update was just released today for AGESA 1.0.0.6a, so I'll need to see how that impacts things, but in this one case at least, things appear to not wonky.