That's what the manual on fedora says too, but it is disabled by default. I admit, I didn't try building from pristine source, so it could be patched!
https://src.fedoraproject.org/rpms/xterm/blob/rawhide/f/xter...
Interesting idea, but I don't think that's what happens:
https://sources.debian.org/src/xterm/375-1/debian/rules/#L22