@mmcm @256
Seems a good fork exists:

github.com/hakuna-m/wubiuefi/

and general chat about it

askubuntu.com/questions/654990

(especially liked the 'it's not supported' being repeated but people saying it works fine (yes pinch of salt there also but a lot seems like there is a difference between 'we don't support / encourage it' and "it's more possible than not, do a backup first".)