What pads are you running? I was just looking into resin pistons and shimano apparently doesn't rate their calipers with resin pistons for sintered pads.
First set, came with the caliper, the next set is a COOMA SPORT semi-metalic set from Aliexpress:
https://www.aliexpress.us/item/3256803539662365.html?FYI, I am running a 203 rotor with the Frog Wake brake.
