I've managed to install last 918+ release 6.2.3 in my terramaster F5-221, without needing any driver apart from the native ones.
First of all, I didn't purchase a vga to 12pin adaptor as this nas does not count with a 12 pin header as a video output. Luckily, I just needed to break a tab to uncover the hdmi port in the back of the nas to access to a video output. This way, by connecting the HDMI to a screen and an USB keyboard, I have access to the bios, and I can override the boot drive. I cant change the boot order permanently, as the bios is locked to not allow that, but Ive discovered a workarround that I'll explain later.
I've flashed the 1.04b for 918+ in a cruzer fit 2.0 flash drive, and It booted up. I had to mount the usb in my computer, tweak the grub.config for updating the vid and pid the flash drive and the mac address of the network adaptors. Then booted again, this time I've installed synology, even, using an official image directly donwloaded by the wizard. And all worked perfectly. Finally, I had to tweak a little bit the bios, to teach it to boot from the flash drive instead of the disks. As the drives are configured as legacy, and the flash drive has both legacy and UEFI boot options, I've configured the bios, in the boot tab, for booting only UEFI disks, and that's it!
