G'day
Smokey, sorry to be so slow replying but me time ain't me own all that much these days. To answer your question, blood-oath there's a good reason why the NRA (National Regulatory Authority) won't get involved in this sort of thing is the same as for any other type of EOSID... disregarding the fact that Pans Ops leaves us in "no man's land", the plethora of aircraft types that have different performance factors would be much too hard for us to contemplate.
Besides... what would blokes like you and
j_t do for an income if we got into that line of work?
The real problem is that most NRA employ very few people to undertake procedure design and, in the case of those NRA who outsource procedure design, the rules in the delegation will be in words to the effect that designs must continue to meet TERPs/PANS OPS criteria, as applicable.
We really aren't performance engineers and, for those of us who've been around long enough to have a fair idea about actual performance, we know enough to not stick our necks out. It only takes one claim against the NRA for the crap to run downhill to the poor old/young procedure designer.
And, after that, where do we draw the line? Do we then provide procedures for 2 engines inop? 3 engines inop? Having seen a LOT of "bush lawyers" during my career, I feel absolutely certain that if we produced a 1-engine inop procedure, we'd be accused of contributing to something other than a level playing field that advantages the 1-engine-inop case over the 2 or more engine inop case.
The legal and practical problems are truly massive.