Great news! I hope it continues to work well for you.
The two lines that seem to be required (based on my extensive testing) are:
dir_cache_off=yes
mc_on=no
When either of those is missing, I can reproduce the directory caching issue easily. The real question is whether any of the others help to reduce the issue even more. All I can say is that with AutoMounter and the full nsmb.conf, I’ve been running without issue for over a month now.
