If that (0.5mm) is the difference in overall height from the pin to the outer edge of the crown it's huge and needs to be compensated for by an equally large increase in gasket thickness to retain stock compression.
A 0.5mm taller piston will sit 0.5mm further up the barrel and reduce squish by 0.5mm.

If the piston dome is of a different radius but the pin to crown edge measurment is the same you need to work out the new compression ratio and make sure you don't change it too much.
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