Again last night I confirmed that the single card ran fine and it did for half an hour no issue. I enable crossfire again and then the crashing resumed within minutes.
I updated driver using the proper method of uninstalling, sweeping, reinstalling, checked the CAP was up to date and still the problem remained.
I got to thinking about the whole 'system' and not just the video card, drivers, and the game. I've got my system set to where Firefox always loads with Google in one tab and YouTube open to a video in my 'favorites' in another. I'm not a huge fan of most game music, so I have a playlist of 50+ songs that I roll through no matter what game I'm playing.
I am aware that many YouTube videos cause my primary card to run at 400/900 MHz core/memory, but I use AMD GPU tool to force it to my factory overclock max of 775/1000 to match the second card so I figured I was OK. If I didn't do this it would cause a slight but highly annoying jerking in all my games, but everything ran fine with this 'fix'.
Out of desperation I changed my startup routine so that FireFox would not load on startup, restarted the computer, ran STO and played for an hour with Crossfire enabled with zero crashes.
There is still the well documented issues that exist with AMD cards playing STO, but at least I can play now without crashing, which is great.
Thanks for the help!