FORGOT THE MOST OBVIOUS POINT

The TBM pilot was at 28,000 feet and declared that he had a problem and wanted lower;
he asked twice and was finally told he could descend to 20,000 feet.

THAT WAIT COST HIM HIS LIFE

(he only got to 25,000 feet before he succumbed to Hypoxia)
If he immediately had started down and gone down to 14,000 he would be alive today

RULE

LOSS OF PRESSURIZATION
                                                      DOWN NOW
No asking; no waiting

i have practiced emergency descent in Lancair, MU2 and Cessna 340

if you are at 28,000 feet and can descend at 6,000 feet per minute it will take two long minutes to get to
14,000 feet.
                      that is a long time and a serious rate of descent

at 3000 feet per minute it will take  two minutes to get to 22,000 feet. you have passed out in those two minutes
(unless you  are a 19 year old athlete or military pilot)

THIS IS SERIOUS BUSINESS
                                                     And it is life or death moment