Safe to run from 13.8V power source?

I plan on running my observatory with UDOO X86 Ultra I got and would just like a confirmation if it's safe to run from the same 13.8V power source I use to power all the other equipment there or do I have to provide a strictly 12V source somehow. The documentation says 12V +- 5% which is fairly strict as 12V equipment usually is fine with 13.8V as well. I tried to decipher the schematics and as far as I can tell from the data sheets for the power converter chips should be able to handle it (RT8231AGQW Vin Max is 26V, RT7243GQW 18V, RT7231GQW 18V, RT8175AGQW 25V, RT8297B 17V). I don't plan on using SATA disk which I guess would use the 12V line as such.

 

SATA power doesn't have 12 V at all - only 5V.

 

Your assessment is probably correct.
Except that it is inconsistent with the factory provided spec thus I would not recommend publicizing it.
Best approach is to use this approach: YMMV.

 

I would definitely NOT recommend it... Or at least, don't expect good things to happen if you try.