Often there isn't a lot of value for an existing user to update to a "point release". However, we have made a ton of changes/improvements for v16.1 and Nextcloud is a particular case in point.

TKLBAM can be useful to transfer data between instances, but in this case, a default TKLBAM restore would overwrite some of the improvements/bugfixes we've done for this release. So your suggestion sounds like a good way to go to me.

FWIW, improving the way that TKLBAM works between releases (i.e. migrating your data to a newer release) is something we're hoping to work on in the future...

But until then, yes you should only need to dump the 'nextcloud' db, copy across the /var/www/nextcloud dir. Then re-running the "20regen-nextcloud-secrets init script should update the Nextcloud MySQL/MariaDB user credentials. I.e.:

/usr/lib/inithooks/firstboot.d/20regen-nextcloud-secrets

Also, one of the changes for v16.1 is that we've moved the Nextcloud user data dir (now /var/www/nextcloud-data) outside the Nextcloud webroot (still /var/www/nextcloud). So I would recommend either moving your data into that dir too or removing the dir (to avoid confusion at some later date...). From what I can gather, it is possible to manually move your existing data outside the webroot. But their forums are so slow to load that I can't give you any guidance on that. If you do that, it'd be great to hear how it goes (and please feel free to share how you did it and/or ask for assistance).