Docker containers are fine. I've moved between 5 NAS' over the years and docker has enabled it to be seemless.

rsync data directories. docker compose up. Done.

On the consumer or even prosumer nas products which have a semi-locked down system (ie Truenas/qnap/Synology). Technically you have root but as soon as you update the OS all/most of the changes end up being broken. Yes you could probably do something and deal with it. But personally I've spent too long babysitting it on the first and second nas that I no longer care.