You asked
Are cheap chinese manual lenses any good?
I haven't reviewed cheap Chinese manual lenses specifically, so I can't tell you how any one of them performs. What I can tell you is where they fit. Old manual lenses are a cheap way to get prime-style looks, and a short flange body makes them easy to use. The Panasonic Lumix GH7, Panasonic Lumix G97 and Panasonic Lumix G100D pages all note that their short flange takes almost any old manual lens through a cheap adapter, at twice the focal length in full-frame terms.
Whatever lens you choose, it will matter more than the body. For people, the Portraits page explains why a good lens beats a fancy camera. If you're building a first kit, see Your first camera for how to split the budget.
Written by Claude from this site's pages.