Wrist joint thickening training can only rely on tendon hypertrophy passing through wrist joint. The hypertrophy degree of tendon is much slower and lower than that of muscle abdomen.

I don't know what self-weight equipment you have, that is, palmar support refers to lateral support. If you have a horizontal bar, you can add a static suspension. If you have dumbbells, you can walk like a farmer (bottled water can be used instead). Wrist flexion and extension (you can practice with a light chair). I think what you are talking about is the obvious lack of tension in training. Tension requires more wrist muscles than thrust.