(Another) Logging of PIC time-135 question

[SkyRider68]

Hi, I'm a new poster looking for further consensus on questions I have posed to other pilots and/or operations people regarding logging of PIC time.
The scenario:

I am employed at the rank of First Officer for a 135 on-demand operator, flying jets in passenger-carrying operations. I hold an ATP certificate and I am type-rated in the two types of airplanes I fly for this operator. Our charter flights are always flown 135, but we also crew "managed aircraft" flown under Part 91 rules for the private owners.

As an upgrade candidate, I have been flying from the left seat (I realize seat position is not really an issue) as sole manipulator with my ATP, type ratings, and *all* required currency and signoffs (293, 297, and 299) needed for a PIC, even though my operator has yet to officially designate me as Captain on any 135 flights.

My question is, can I legitimately log these 135 legs in my logbook as PIC time? I am hearing *many* conflicting opinions from people in the biz. I know the airlines don't want to see any of it counted because I don't have the "Captain" designation, but what about for other 135 or 91 corporate jobs? It seems like a lot of the experience requirements (including PIC time) for these positions are driven by the insurance companies. What are they looking for?

As for the 91 legs, most people are telling me that I am free and clear to log that as PIC so long as I am typed, current, and sole manipulator. Agree or disagree?

I've read an FAA interpretation circulating on the internet that said there is a distinction between "logging" PIC time in a logbook versus "serving" as a PIC in a 121/135 operation. I am leaning towards logging the time in my logbook as PIC at this point, but would like to hear some feedback. I'm an honest pilot and do not want to be accused of falsification down the road.

Thanks in advance for some intelligent discussion on this. :-)