I found a few databases for EF lenses and a good article from Rudy Winston, but nothing complete for RF lenses.
You can also try Canon Sales. I'm sure they have these.
Bay Area - CA
~R5 C (22.214.171.124) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, +RF 1.4x TC, +Canon Control Ring, BG-R10~DxO PhotoLab Elite ~DaVinci Resolve ~Windows11 Pro ~ImageClass MF644Cdw ~Pixel6 ~CarePaks Are Worth It
IMHO, the only thing MTF charts tell you is how good the lens is at taking fancy pictures of charts. Tells you little to nothing about how well a lens preforms in the real world situations. They do give the lab guys something to do and talk about. 🤔
click on image of lens, e.g. https://cweb.canon.jp/eos/rf/lineup/rf16-f28/
Then click on "specification" if your browser translates the page to English, e.g. https://cweb.canon.jp/eos/rf/lineup/rf16-f28/spec.html
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
04/20/2023: New firmware version 1.4.1 is available for EOS R3
03/30/2023: New firmware updates are available.
2/07/2023: New product announcements!EOS R8 EOS R50RF-S55-210mm F5-7.1 IS STMRF24-50mm F4.5-6.3 IS STMRF15-30mm F4.5-6.3 IS STM