I think you answered your own question. If you have 22 rigs on SmOS, and the 2 Asus B250 motherboard rigs regularly have problems, the problem is not SmOS. Google it and you'll find EVERYONE has problems with the B250, and NOONE is running 19-GPU's stable. Ask ASUS. Good luck!
Asus B250 Mining Expert mobo seems to work faulty on Simplemining! needs an update ASAP! I have 22 rigs on simpleminig, 2 of them run on B250 Mining Expert mobos, they get completely locked up once a day. It's very frustrating. Please contact me or do something about my favorite mining OS. I need to run those rigs 24/7 ![Embarrassed](https://bitcointalk.org/Smileys/default/embarrassed.gif)
![Embarrassed](https://bitcointalk.org/Smileys/default/embarrassed.gif)
The thing is I only run 8x 1080ti on this ASUS B250 Mining Expert, I never tried more than that. 8 GPUs and the whole system gets locked daily!