Finding and editing settings.json is easy, now that I found my way around.
- grant write permissions for "other" to transmission jail's dataset. These permissions reset anyway after i turn transmission pugin back on (must be off to preserve edited changes)
- have a share that leads to transmission "home" (currently on FreeNas 11.2 that is /mnt/<my_pool>/iocage/jails/transmission/root/usr/local/etc/transmission/home/). Normally it is human-inaccessible at all. Settings.json is here and now can be edited-overwritten
What I don't know is how I type the password.
Settings reference says it is a string, but it is always hashed. When I retype it here, I lose access to transmission via anything.