Unlike the usual fanless mini PCs that are restricted to ULV processors, the Atlast! Sigao Model B includes a desktop-grade Intel Core i9-10900T CPU coupled with up to 64 GB of DDR4-2666 RAM and NVMe storage solutions like Samsung's 970 EVO SSDs, which are notorious for high temperatures in full load. These components can get quite hot without proper ventilation, but the Atlast! passive cooling solution still manages to keep internal temperatures at around 46 degrees C, even without a venting system.
https://www.notebookcheck.net/Atlast-Solutions-presents-silent-mini-PC-powered-by-Intel-s-10-core-i9-10900T-CPUs.532937.0.html
If you can't afford a custom mobo/PSU, you probably shouldn't be in the OEM business. And you certainly aren't on the map with your brand.
I know this falls on the deaf ears of 10,000 totally legit "PC makers", everyone's favourites really, such as the renowned "LeeeLoo" and "EeeezyPeeCee". Whatever. Anyone with a semblance of self-respect would just get an IdeaCentre Mini or something.