There's an unofficial rust implementation[0] that runs in a docker image and uses sqlite for persistence. I don't know what the details are for storing data at-rest in the sqlite db, but it's supposed to be much better on system resources.
The 2-4GB RAM isn’t a hard requirement in my experience. I initially had the whole Docker compose stack running on a single $5 DigitalOcean droplet, and didn’t experience any issues for personal usage. Since they also distribute it to you as Docker containers, you can also set resource limits, specifically for the MSSQL container, to prevent it from hogging all the RAM.
I currently have my Bitwarden instance hosted on my Docker swarm cluster, which is just 3 $5 DO droplets and 1 with like 2GB and RAM and 2vCPUs. But, a quick look shows that currently all the BW containers are running on the $5 ones. I have the MSSQL container’s RAM limited to 1GB as well.
As for the x86 requirement, that’s likely the case, I’m assuming you mentioned it because you’d like to run it on some ARM device like a RPi. I haven’t tried running their containers on an ARM device so I can’t say they’ll be compatible, but I know docker’s ARM compatibility has improved so maybe someone has got them running on some ARM device.
I've been pretty happy with https://www.passwordstore.org/ Keeps passwords encrypted in git, and there's plugins and open source apps for just about everything. Throw your store in a private repo somewhere and you're good to go, no need to worry about Bitwarden or Lastpass or anyone else going out of business.
If you aren't hitting it hard (hosting more than a few connections) you won't notice much limiting to 1GB RAM... I run a couple projects with MS-SQL docker containers and 1GB limit...
I tend to change the name and port mapping as necessary depending on use, but that's the quickest way to get a server up for MS-SQL... can use SQL Server Management Studio (windows) or Azure Data Studio [1][ (electron, formerly SQL Operations Studio) which is cross platform[2].
