Hi @sidor!
There is a post-config hacks you can use. Simply write a shell script that apply your config changes/tweaks and put it here:
/zynthian/zynthian-my-data/scripts/update_zynthian_sys.sh
It will be executed just after every config save.
Yes. This should be documented on the wiki. Same as “first boot” hooks! (@mheidt, do you remember that? Are you still using it?)
Regards!