Just want you to know that MSIX exist

[FixRM]

I'm not a troll, I'm big fan of your other tool ILRepack Build Task. Recently I solved similar problem and ended up with MSIX from Microsoft https://docs.microsoft.com/en-us/windows/msix/app-installer/web-install-iis. It support "side loading" from URL or Folder as well as publishing in a Store. It also support installing directly from web without need of downloading installer (not working now) and automatically download only diff when installing update. It short - have a look.