Just in case anyone have the same doubts that I did...|
To flash the LapBook BIOS/UEFI you have to put the contents of the uncompressed "LapBook 14.1 BIOS 20161230" folder in a FAT32 formatted usb key and restart the laptop. You can skip flashing during boot pressing some key, but if you don't, “startup.nsh” will flash automatically. It took about less than 5 minutes. With this update now I have the "OS Select" option in my UEFI and finally could test that Linux runs ok. So far I have tried Xubuntu and Linux Mint, both working ok right out of the box.
I think the option “OS Select” must be some kind of Secure Boot toggle, because in “Windows” mode I cannot run Linux, but in “Linux” mode I can run both.