can we please all agree that they need to lose their online-instal-only scheme

No, sir. I cannot agree with that.
For me, XLNAudio's installer is just great and I appriciate that it makes it easy to stay up to date with the latest versions of all of their plugins in one go. Compare it to the installers of NI, Izotope or Toontrack, who's products I also love. This one is just smarter!

Best Regards
Ludvig