you can't really fake the labor that goes into mastering a craft any more significantly than one can fake labor at a white collar job, let alone some level of institutional involvement that any professional pursuit would end up with (i.e., showing a work at the gallery on main st or giving workshops at the community center), so this isn't actually that challenging of a question in practice. even with highly conceptual work there's still an involved studio/research practice to audit

if your artistic practice is truly so abstract that you can't prove labor by any material means then you probably just won't get subsidized for it.