j.t.
I defer to your acknowledged background in these matters.
However, I've know several pilots without engineering tickets who were more than competent in runway analysis. The mechanics of the thing tend to be more boring than anything else. The interest lies in getting the obstacle data right .. although that, too, is becoming easier with improving technology.
Where the typical pilot might start to run out of steam is in the routine performance work associated with operational optimisation and so forth.
On the other hand, it probably makes more sense to have engineers (preferably with piloting backgrounds) do the RTOW work ?
At least three such in the PPRuNe fraternity come to mind.
One of my work associates is a biz jet pilot and a real expert on AC 120-91 and OEI requirements overall. He and some other real experts in the field have been meeting recently over the issue of lack of meaningful navigation guidance for an extended takeoff flight path and transition to en route requirements at airports with significant, high terrain all around.
The transition to RNAV for this purpose has fallen horribly behind. The typical performance engineer doesn't understand performance based navigation. And, in the U.S. at least the typical procedures specialist doesn't understand the extended OEI case. In some cases they are still using VOR facilites that cannot be received, or in some cases where then can, they are in a sector of restricted radials.
My view is that you need site-specific collaboration between a performance engineer, a terps (or pans-ops if you will) specialist, and a technical pilot to provide an RNAV performance based navigation (PNB) solution to the complex, extended takeoff flight path all the way into the OEI en route environment, and then with the option of tactical diversion while en route.
In the U.S. FAR 121.91 is terribly obsolete. Although there may still be a requirement to provide +/- 5 statute miles en route lateral protection for "DC-6" OEI en route ops in the mountains, it is absurd for the PNB capable aircraft. Something on the order of +/- 2 nautical miles would be more in order, with provision for reductions from that for the more cabable PNB capable aircraft.
121.191 has lighted airways and DC-6Bs (perhaps even DC-4s) embedded in its arcane provisions. I suspect the rest of the world is no better off, for the most part.