In blablaa land, the book sources say pretty much the same (guide was published just 2-3 years before the first PPH edition, then never updated - was it a source of inspiration ?)
(in NL, a muscle relaxant can seal a deal, late to the party. Isn't a late injection of N given by the some, not all, swiss clinics, or muscle relaxant ? asking)
6g fatal, more preferred. Sitting on 6g ? > precautions (AE, tolerance) encouraged.
The main difference is that the guide usually backup the claims with data (from NL/CH/OR state) for extra depth, when PPH choose not to cite references.
(Indeed, for all methods, the guide often gives clear directions, maybe at the counterparty of doing it awkwardly on the safe side - including being more sceptical / excluding. PPH is more authoritative / sometimes vague, with less exemple references)
Lethality never matters if quantity sufficient. If tolerance have incidence, it is barely developed.
There's left to explain the variable speeds (2-24 hours at an occurence of 7-9% from organisation data at 9-12g ...where PPH "estimates" the escaping tail at <1%, not caring to share evidence), whose reasons are not entirely detailed with theories (PPH attributes "some" cases to anti-psychotics and chronic alcoholism. What about the rest ?).
Personally, I contacted Dignitas and Exit ADMD last month (as a non-member) and they wouldn't handle time to death stats anymore (recent and past - before, they were published openly on sites)
Not on any addiction, my night would still be arranged for a long 12+ hours one, rather leaning towards past a day, because I'm in a particular situation, not medically insured atm, that cannot risk failure from rescue, neither a major financial leak for my relatives, if hospitalised