Did you test it today?
Early days, but 10.5.7 installed without a glitch, then I used the Canon 5DMKII tethered and with a hot folder to link with Lightroom and everything was working perfectly as far as I could tell. I also installed the latest Canon upgrades (EOS Utility update 2.6.1) just before upgrading to 10.5.7. I tried just over 150 consecutive pictures, some in very rapid bursts of 10/15, and it didn't crash, so it appears to be fixed now. Before it used to crash at around 100 pictures.
I also tried it with my Leaf software (which was working fine before the upgrade) and it all seemed to work just as good after the upgrade.
Happy so far.