I've got a $50 USD 6500T with 25+ docker containers including jellyfin and it is amazing. It isn't the drive space you want but pure cli Linux is very lightweight.

my main concern is it needs to be more capible than a nas /while being cheap af /with decent selfhosting options

I think that CPU only supports up to 8GB RAM. Also the m2 is only for Wifi cards I think.

I have a somewhat similar ASUS board and it is quite ok otherwise, but don't expect wonders from that CPU.

A bit annoying will be that you need to either use one of the four SATA ports for the system drive, or find some way to boot from the PCIe 1x port. The similar ASUS board that I have does not support booting from NVMe drives though, so even if you added an adapter for this it probably wouldn't work (maybe if there is an BIOS update for it).

You could boot from a USB3 drive... not ideal but workable. Or add more SATA ports via an PCIe 1x extension card... but those might be hard to find, usually they require a longer (4x?) PCIe port.

P.S.: if you end up buying that board I can sell you 2x 4GB DDR3 SODIMMs that I have currently no use for :p

Have you heard of capital letters and punctuation?

That's too hard to read.