Clive George ( snipped-for-privacy@xxxx-x.fsnet.co.uk) gurgled happily, sounding much like they were saying :
Indeed. In fact, I'd be even less likely to get under it with it on full- high.
All the suspension lever does is move the "balance point" of the height correctors. When the car's higher than this, the height corrector lets pressurised fluid back to the reservoir. When it's lower, it lets it in to the suspension "dead end".
When the car's in "full high", the balance point is beyond the limit of suspension travel, so there's 2500psi being shoved in all the time. That, IME, is when borderline pipes burst.
You've also got the fact that the reason most people'll be under a Xant is to re-attach the plastic clip - which'll mean a tug on the height corrector. Which'll mean that the car may well suddenly think it's too high, regardless of the lever position. Which'll let fluid out. Which'll cause the car to come down.
"On your head be it" has never been more apposite.