Docs, could 0.2mm kidney stone cause issues?

Yes, occasionally... I assumed you meant a stone of <2 mm, not <0.2 mm. Largely, a stone <4 mm has an 80% of chance to pass spontaneously in 2 weeks with expected coping with pain, but it doesn't mean a stone of 2 mm will always pass; in fact, occasionally, a stone of 2 mm may still require intervention. So, it's said: despite medical advance, all care is still based on indirect evidence from past experience...