Why not split the difference and do both. Hdd for storage and SSD for services/containers. To help with the power load/performance hit I’d recommend using a usb to sata adapter that has external power. Overall though it sounds like a micro optipl x would be great for you. They’re cheap, more powerful, but still sip power, and usually can fit nvme and 2.5" drives together.
Is the Hba in a traditional server case with lots of airflow? My 9207-8i displayed a similar issue bc it didn’t have enough direct cooling (it’s not in a traditional server/case.) it would never show more than 2 drives at a time and they would often vanish. Once I mounted a fan to it, the Hba has been stable and showing every drive I attach
I tell people, like my friend that wanted a bunch of drivel kids stuff, that if they give me 2 hard drives I’ll set them up as their own library.
That’s unfortunate you have to put in a ticket. They should be able to help you with this during a 5-10m phone call. Hopefully they get to your ticket in a timely manner
Can the ISP at the remote location remove your remote location from the NAT? I have a similar issue where sometimes it’s will reset and my services are inaccessible. A quick call to support usually has the problem fixed in a few minutes.
Fishwaldo is pretty active in the #pinetab chat from what I’ve seen. If you have matrix, discord, or irc you could jump into the pine64 chats and ask him
Only my emby and ombi containers has an open path in/out, everything else is local or VPN only
Volumio might work. It has a subsonic plugin.
Miridore is self hosted and free
If you want to be able to watch/preview the HEIC images, you can edit the available mime type for Nextcloud’s Viewer. (I do this to our company’s NC so customers can use viewer for PDFs and employees can get previews/thumbnails of TIFFs, AIs and PSDs. For HEIC, just go to your NC’s ‘apps/viewer/js/viewer-main.js’ and add ‘image/heic’ and ‘image/heic-sequence’ to the mimetype list (about halfway down, I hgihly recommend using VSCode+a formatter to make finding it easier)
As said in another comment a bare metal Debian install likely wouldn’t be very smooth, or you’d have to run it within Android. Alternatively, if you want to run Linux directly on the phone you could try postmarketOS https://wiki.postmarketos.org/wiki/OnePlus_5T_(oneplus-dumpling)
I can’t help as much with the exposing outward (I’m a basic bitch and just use ddns to expose mine since I can’t get a dedicated IP) but a separate vlan with rules to allow your primary vlan devices to see/talk to it, and block it to be able to see out of it’s own VLAN, would definitely be recommended.