I designed thumbsticks for the Ayn Odin 2 that fit the Skull & Co Nintendo Switch joystick caps (link below). This is the 10th iteration and they have a snug fit and flat design on the top to fit the skull & Co caps.

Skull & Co thumbstick caps - https://www.amazon.com/dp/B071FMCLZ7?psc=1&ref=ppx_yo2ov_dt_b_product_details

PS5 cap design is available as well:  https://makerworld.com/en/models/254052#profileId-270463