Hey martin think about a tablet edition with a 32bit UEFI bootloader for the ATOM processors.
I have a tablet with a Z3735F processor and it needs a 32bit UEFI bootloader. I have ran your UbuntuMATE LIVE on this tablet putting a 32bit UEFI loader in the ISO files but can not install it. the only other thing it needs is to get the wifi working. there is a website showing how to get everything installed and working but would be nice to have a working ISO.
I cant find any distro that supports tablets with this processor and that have a ISO with the 32bit UEFI bootloader.