yes and no. Here's what I understand from my time with an automotive OEM; The skirt moly coat is intended to transfer to the cylinder wall within the first few hours of engine operation, embedding itself in the wall crosshatch. It's not intended to replace oil film, only enhance lubrication during certain operating conditions, i.e., cold start. Therefore, increasing the piston to wall clearance is neither required or desired.
As for piston thermal plasticity; the information in that post is very accurate, for modern pistons. All/most post-war piston designs include a 'cam ground' profile, to accommodate different expansion rates at different points in the piston. The most thermally sensitive pistons are forged aluminum, given their dramatically different densities at different points of the structure. Therefore, they must run with the most piston to wall clearance, resulting in signiificant noise and skirt wear during cold engine operation. The least sensitive pistons are cast hypereutectic (greater than 12% silicon content) aluminum, because of the consistency of material density in a casting, and thermal rejection of hypereutectic alloys. These can run with very little piston to wall clearance, and can be sensitive poor lubrication as a result. The moly coatings help the longevity of these pistons.
Our antique cast aluminum pistons, most likely of a eutectic alloy (around 9%-12%, I doubt they're hypoeutectic; 8% or less), experience less severve thermal expansion and distortion than forged pistons, and can survive a pretty loose piston to wall clearance. If the moly coating were kept to a minimum, say 0.025mm cumulative between both skirts, the rapid transfer to the cylinder walls would result in near normal clearances relatively quickly. By applying a thermal barrier to the top of the piston, in our engines, I wouldn't expect to significantly affect the size and shape of the piston, but would expect to see slightly less heat transferred to the engine oil. The slightly lower piston temps should also limit skirt expansion, making a slightly reduced piston to wall clearance because of the moly coating, much less of a concern.
The only to know is to do it, then document the results.
