cross-compiling all module dependencies (forget I even said that), there is no way to get any C application to work on a foreign platform. XS modules fall into that category.

This is partially false. While I don't believe it's reasonable or worth the time to cross-compile perl modules, as I think you'd end up arguing with Module::Build and ExtUtils::MakeMaker more than anything else — it is possible to reliably cross-compile all sorts of things. I used to maintain a 3d bumpercars type game (with spaceships) that was never finished (of course) that pulled in SDL/GL and various other things and compiled for ELF and win32 from a single platform.

Should you choose to do so, you'll find tons of documentation and support for cross compiling under many platforms.