Maybe something built around the RK3399 SoC? It's support, while not being perfect, is well matured. The Nanopi R4S is such a workhorse without unneeded stuff, just dual LAN and dual USB3. That's it.
I tried using it as NAS by myself a while ago but unfortunately I could not manage to run stable for a longer time.
ATM I am using the Station P1 for that purpose which is kind a not what the board is designed for but it runs stable for long now. One Lan and one USB3 only but you can attach a NVMe.
The board inside is a T-Firefly ROC RK3399 PC PLUS.
Also a great board that has GBe and USB3 in a very small form factor is the Nanopi Neo 3. I used to have one but I managed to break it.