there is no guarantee that the output remains wellformed when tickers are patched or newly created

F.U.D. Demonstrate how that's likely to break.

XML::Fling was designed to take the important (likely to break) aspects of well-formed XML into account. Sure, you can do really stupid things with it that would produce obviously broken XML because it doesn't waste time checking for obviously stupid things, but I don't see a problem there.

And you can stop suggesting alternate ways of handling control characters. I've been through a bunch but when XML 1.1 showed signs of sanity, the two choices of "strip 'em" and "leave 'em be" became the hands-down winners.

So you are restricted to the ways of using Genx that I've already stated: As an optional alternative or when it supports what we already do.