eBay is your friend, Shield came out about 9 years ago so lots on the used market. Also the phoning home for the paranoid can also be handled. Since it’s been around for so long there’s not a lot left someone hasn’t already figured out. Maybe not the perfect answer but worth considering. As a media player it just works and it’s tried and true.
I have not tried shucking drives but I imagine they should work. Currently have 20tb Seagate ironwolf ST20000NT001. The script takes two seconds to run and needs to be redone everytime you update the Synology software which doesn’t seem to be overly frequent. Running the script or not you have the same full functionality. Script just removes the warnings.
Docker as mentioned above is great especially if you’re going down the homelab rabbit hole. You’ll find it really useful to get familiar with for future projects.
Another alternative is to install DietPi. It’s an operating system for a raspberry pi. It has all these programs you mentioned with install scripts including docker and installing (and updating) is as easy as checking a box. Also has a pretty good community in case you run into an edge case.