The answer is likely that the potting material is poly urethane based. Similar to seat foam buns it degrades over time. It may have been improperly mixed in ratio, speeding degration.
Not to start a flame war, but consider hiding a HEI in there.
Those new HEI units I see for the mopars look great. I'm an MSD guy. Never seen an MSD do this, or fail for that matter but the msd sits on legs so if it did it wouldn't affect paint.