I think that there are more issues with conversion kits to change your DI rifle to piston than there is for a dedicated piston AR design such as a Ruger SR556 or HK416.
The main issue with conversions is that the AR "direct impingement" system is really a piston that is inline with the bolt face, so that the piston forces are straight back down the axis of the bolt carrier.
For a gas piston conversion, the DI bolt carrier's gas key is replaced with a solid surface for the op rod to smack, and that off-axis force causes the bolt carrier to tilt back, often putting wear on the buffer tube area.
Dedicated gas piston designs use a bolt carrier and upper designed to compensate for that offset whack by the op rod.
Gas piston bolt carrier:
