Best practice for local / remote access

Hey there, Nextcloud newb. Sorry if this is an obvious one but my searches are bringing up everything else except the answer I need.

If I’m using Nextcloud on my home NAS, I obviously want to let laptop/desktop access via local IP, but when I’m away and I want to access the files, I’d use a DDNS address.

So if I don’t want to keep changing things, do I just use the remote address also while I’m on my local network? Will it know that it doesnt need to send and receive any data over the internet automatically?

I did an iperf test either way, and the remote address is slower than the local address, but not by a lot.
Is this the recommended way to have things set up? i.e just always use the remote address?

I always use my FQDN, in your case DDNS Address, it works fine from everywhere.
If you have problems with Speed in LAN, ether edit your hosts file to point it to the Local IP (when you at home), or user you DNS Server (like Pi-hole and point your DDNS name to the exact LAN IP.

Oh man I feel a bit silly for not thinking of that.

Further to this, I’m now faced with the issue of multiple copies of data filling up space.
I basically want a local NAS functionality, that can be accessed while away and also shared with colleagues. I originally had thought to solve to data issue, Just set Nextcloud not to synch anything about 50MB, but the problem there is that the folder structure is also not visible. I need to be able to see everything but not copy it to the device.

I thought WebDav might be more suitable then to use at home, but it is painful sllllloooowwww. Just making the connection to WebDav locally seems to take about 20secs to authenticate and then even reading the folder structure is like watching paint dry.

So what if I share the NextCloud data folder via SMB? Would changed made to the folder be detected by NextCloud and its database updated? Or is this not the way to go?

Basically this is not how it is designed to make changes directly to the Data folder.
You could move your folder out and added them to Nextcloud as external Local storage, in this case you can run cron job for a quicker rescan.

Otherwise you have to ether know exact folder that changed, or rescan whole FS.