It took me a couple read throughs to figure out what you were talking about. You have made several incorrect assumptions, but I did eventually figure out where you went.
Syncthing, and a mobile app, in the context of file synchronization, are indicative of endpoints where users make files to be sync’d with other endpoints. Having a server online 24/7 like TrueNAS will facilitate that, and sometimes make it faster. In my case, my endpoints will primarily be laptops and maybe a phone or two.
My intended use-case for this is to keep some files synchronized between laptops (and maybe phones), just like I used to do back in the day with SyncThing. The point of inserting TrueNAS into the mix is for a 24/7 server to minimize the problems of file-based synching of SyncThing that I encountered when I sued it in the past. I’ve asked the SyncThing forum if they still do file based sync, or if they have moved to block based sync, but my post is still stuck in a spam filter.
The installation I’m referring to is not in the base OS, but the built-in app ecosystem accessible in the web UI. It probably uses docker, but I haven’t looked into it aside from the intro documentation and noting it was kind of weird people want to cram so much stuff into a NAS. From what I recall, there’s some kind of picker/chooser in the TrueNAS web UI to install things.
As far as putting NextCloud on TrueNAS, I would have never thought to do that. I found 2 interesting links:
I’ve only read the intro, but now I kinda wanna do that. However, I’ll have to build a new environment to test that out, rather than risk borking my main storage.
If the NextCloud app finally has 2 way sync, then that might fill my file sync needs. Here’s hoping it can do it on the SD card.