Finally it is more compressible than the glycol and ester fluids. This compressibility goes up with temperature.
I concur with most of your other points, but I have "read" the compressibility issue with DOT5 is, it traps/entrains air when pouring, and first impressions just after installing, leads to the compressibility observations, unfairly, if confirmable. The rising temp issue leading to increased compressibility, is the first I have heard of that condition.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
