Flattering non-bounce handheld light?

Most of the techniques and gear I've read about for single-photographer handheld spontaneous portrait shooting involve bouncing a flash off the ceiling and walls onto the subject for a soft effect. I need to do this type of shooting in a dark convention hall with a very high, irregular ceiling that is not likely to be useful for bouncing. I will be using a Nikon D3s and either Nikon flash, a LitePanels MicroPro LED light, or anything else I can rent. Subject matter is mostly one or two people in costume, head-and-shoulders or three-quarters. I'm looking for a quality level a good cut above snapshots.

In this case, what is a good technique?

1) Carrying a handheld reflector like a Lastolite Trigrip in my left hand and a camera in my right hand, bouncing flash off the reflector?

2) Using direct flash with some kind of diffuser?

3) Moving the light way off-camera with a big bracket or handheld pole?

4) Something else?