When building a ranch style house, can a raised-heel (energy) truss design be used to build a hip roof ?

Yes, an energy heel can and should be used with full hip truss roof. Attic trusses can also be used to create storage or additional living space.

Yes, I used raised heel trusses on a hip roof.

If you use Cantilevered trusses, the energy heel is automatically built in. We built a workshop last year and are just finishing a home using hip and multihip roofs with cantilevered trusses. A 6/12 pitch with a 2 foot overhang gives you a full 16 inches at the wall. Soffits are also a breeze with no additional framing required.

Yep, less details in finishing out/closing in the soffit on a full cantilevered truss...

A cantilevered truss automatically make the soffit support. Unfortunately it also provides thermal bridging. If you go with a standard raised heel on an ICF house, you hold it back 2" from the face of the ICF and install 2" foam on the heel. Same would hold for exterior foam on stick built.

So those of you with 6/12 slope and 2' overhang are taking blocking and installing the blocking on each truss side and then taking OSB / foam and fastening the osb/foam to the kneewall location to prevent insulation from going out to the soffit area, and a secure mount for attic baffles?

We use a product called Accu Vent to maintain the soffit to roof ridge vent ventilation path and contain the cellulose or fiberglass blown in insulation. Our passive solar house designs typically have a 4' roof overhang and we use Bruce & Dana perforated metal soffit material that is fastened directly to the 2x6 truss tails. We use energy heel trusses and not canterlevered trusses. We like the finished look better and we prefer to minimize vented cavity volume to avoid trapped moisture issues.

Where is your roof air barrier? What do you mean by "minimize vented cavity volume"?

We do vented attic space using attic trusses for storage space. Ventilation is thru the smaller volume truss tail bay cavities in lieu of larger volume cavity that results from putting soffit on canterlevered trusses.

Where is your roof air barrier? I ask because we used Accu Vent and found it was practically impossible to air seal.

The Accu Vent is entirely in the attic space which is fully vented, so no sealing is required in that location. I suppose I should also say that we only do ICF single level construction. So the living space air leakage concerns are largely the doors, windows and electrical/plumbing penetrations into interior wall assemblies. We typically use polyiso under the attic floor and blown cellulose or fiberglass elsewhere so as to achieve R60 for living space ceiling which is 5/8 drywall conservatively screwed and glued perpendicular to truss cords.

6/12 raised heel, 2' overhang we do not order cantilevered design, use accuvents with baffle and aluminum soffit with an f channel on the house for soffit panels. For wood soffit I nail up a backer.
Non cantilevered trusses have more field adjustability during the truss set, we don't have to rip down subfascia to line up with truss bottoms, cost less, aren't stuck with full heel height soffit lines if the design looks too top heavy in elevations, can't adjust your overhang depth when you might need to with multiple pitches, etc.