I'm integrating Varjo/Vari into a project with customized pipeline definition (material), but GLSL compatible. As far as I've got with Varjo, it seems it cannot produce GLSL in a way that will be possible to use with that format out-of-the-box.
I did some patching that adapted Varjo to generate GLSL while discarding stages/pipeline stuff like in/out blocks, uniforms, etc. This and accessing some internal APIs does allow me to generate pure GLSL libraries that I can embed into aforementioned material definition and feed to a rendering engine.
Would you be interested in incorporating any of those patches and possibly making some internals public? Or, maybe, this use-case is out of Varjo scope?