Minecraft - update CloudNet to 1.15?

Since CloudNet is unfortunately no longer being developed, as I have noticed, there's no way to upgrade to 1.15.

I find that a bit of a shame because I want to make as many versions as possible available to my players.

Now my question: Would it work if you replaced the bungee.jar with a 1.15 bungee file? Or is the Jar somehow edited?

Has anyone done this before?

Yes would work, but it would be better to just use the 1.8 and ViaVersion.

Thanks first of all.

Yes, of course. But for ViaVersion to 1.15 to work, the bungee file must also support 1.15, right? Otherwise the proxy would not let the player up

You can use proxy 1.15 and the players should be able to use it without VV. Otherwise simply 1.8 Proxy and ViaVersion also on the proxy ^^