Again, I'm talking about this "the first ever" event, which isn't a first ever. I'm pretty sure others have done something like this on BKOOL or Zwift to raise money for a cause or just the challenge, but we never heard about it. Michael has done lots of crazy stuff both indoors and outdoors, and I actually think he was one of the first to do an "Everesting" on BKOOL some years ago, where he climbed d'Huez 8 times in a row (without the downhill part).
Today he rides for Team POAUTO on Zwift, so go ahead and race him and compare yourself against him.
Here's his ZP profile:
https://zwiftpower.com/profile.php?z=76018
I have never heard of any UK ultra cyclists either, so don't be sorry about not knowing the Danish ones.