You also self admittedly say two vac pumps are not a bad idea.
Do I?
Fitting an electric backup vac pump (which is a massive clumsy lump) is a bit like replacing an IO540 with a steam engine, and if the plane doesn't fly with it, fitting a second steam engine.
The reality is that when you fly a typical IFR single you accept a lower level of redundancy than when you are flying a twin with both engines fully loaded with accessories. Unless the single is a Cessna 400... or a TBM, etc. And even a twin with two totally separate buses (with crossbars) is unlikely to have two separate pitch/roll sources for the autopilot. Unless it is a 737+
One can improve redundancy but the cost and hassle just goes up and up, because everything that's actually worthwhile safety-wise is a major mod, and sometimes virtually infeasible paperwork-wise.
99% of my high altitude IFR is VMC.
I haven't been to Thailand lately (have a very nice girlfriend, thank you) so pardon me for not knowing that somebody out there has fitted a second (full-size?) alternator to a TB. If you have access to their paperwork I would like to see a copy; it might be useful. Is it on an N-reg? No I didn't think so; I do know one pilot there and you can't keep an N out there permanently.
You seem to have some sort of agenda, Mongo, to pick holes. Have we crossed wires in some other life?