The main file to edit should be smb.conf if any of those template files are used they also get included in the smb.conf if not they are modified copies of smb.conf and more serve as a example config you can choose to replace.
I would recommend to keep the current config, often the problem with these copy configs is that they may are not placed by the gl package but by samba itself, so this means these configuration may not work with gl firmware.
I did not use this feature with GL-iNet software so I don't know.
i did some testing, and i think that is incorrect advice.
after each reboot, whatever changes are made are LOST
if i edit smb.conf.template4, then reboot, the router updates smb.conf
again, i think is incorrect advise, in the forum, there are many examples of changing the samba config.
sure, a router firmware update or luci, could/will overwrite the changes, but that is to be expected.
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i did more research i found several topics from gl-inet staff editing the samba config file.