|readings are important (looking for differences in pressures) a cold test is still valuable. While hot is more accurate to engine condition I generally do cold so temp conditions are better known and easy on the hands.
Also to test is with some oil in the cylinderes to see if ring sealing improves and by how much. A little pressure increase is better than alot.
A final test would be a leak down.
Let us know what differences you get for hot vs cold.
ZUL8TR in Orlando,FL