Flashing truncated Bios to allow 7th gen CPUs

I want to change the bios of my Fujitsu Siemens Esprimo D756 E90 mobo model D3401-A11 with the bios of its sibling mobo D3401-B2. The latter supports 6th gen Skylake and 7th gen Kaby Lake CPUs. My latest mobo bios only supports 6th gen. I want to use Kaby Lake to make transcoding 4K HEVC possible.

I hope I correctly verified that it is possible by truncating the .uba file of the b2 mobo bios with something like [trunc.exe](https://www.softpedia.com/get/System/Sys...runc.shtml) as described here
https://www.bios-mods.com/forum/showthre...?tid=40459
and here
https://www.bios-mods.com/forum/showthre...?tid=40475

and then flash it to my mobo. I guess this is possible because both boards use the same Intel Q150 chipset.

The forum postings only describe flashing with a hardware programmer. So my questions are:

Is it safe to do this?

Is it possible to use the built in possibility to flash the modified bios with a USB drive and Free DOS?

My current bios file pack contains a .upc and a .uba file. So does this mean I have to replace the .uba file with the modified one? What about the .upc file?

I never done something like this so please feel free to treat me like a noob.

Thank you!