I didn't have a delay in my config.g but I added one at the beginning for testing purposes and it does not make any difference (well except that it takes longer ofc).
Sending M98 P"config.g" does not generate any errors.
When I send M112, there are actually no errors and the homing works fine, just like pre 3.4-b5 (even the thing with the different motor speed, might have been a one-time thing)
When I send M999, I get the errors. Also when I change the config.g and reset the board (which probably is also M999?).