RAT 5
Most private biz-jets most likely do what they like: or file FL410 as max
The problem is "doing what they like" cause normalization of deviation in ignoring the rule. Some stay at F410, some use oxygen above F410, some, no doubt ignore the rule as being out of date. The stats of high altitude loss of pressurization support changing the rule or deleting it entirely. The oxygen masks in a side wall cubby (Scott EROS) weren't designed for constant use and constantly being undone and restowed, hence the test function which doesn't require removing the mask.
GF