This. There's also other issues I see need to be overcome. I for instance have a hard time keeping up with one airlines manuals, policies, Op Specs, and other changes. Combining multiple carriers policies and procedures seems like a recipe for a violation.. Every carrier I've worked for has had different procedures for addressing the same issues. SO, either you need to have your contract personnel on one certificate (customer) or risk the DO's job and airlines certificate. I don't think a contractor would be as likely to say "NO!" when pushed. I relate it to former carriers who use lowest bidder for contract maintenance, and almost never had a plane come out of a heavy check in better shape than it went in. There was no "skin in the game" for them.
You say you are dispatching to a domestic/flag standard, but then laud how much other stuff you can do at work and not have responsibility for what decisions you make. This may come off as an insult, but I don't want that attitude in the person planning the flight my mother is on. I have more freedom at a full 121 domestic/flag carrier that I did at a supplemental carrier. If i want an alternate, i put one on. 1-2-3 (or in our case 1-1-2) rule be damned. But I have a reason for it. That was the toughest change going from a supplemental world to a domestic/flag. it felt weird at first, but the more i did it, the more liked it...

. Now, it's weather I don't have to monitor or Notams I don't have to read. That is a definite plus with over 30 flights working at a time.
Like i said, I'm an control freak and a little OCD. I like the operational control aspect. I like taking the responsibility of my decisions and standing behind them when questioned. I make mistakes, and learn.
And lastly, keep in mind that at a supplemental operation, you make be shifting the responsibility to the DO, but you are still exercising the rights and privileges of your FAA certificate. The FAA can (and will.. seen it) take certificate action against you if they feel a situation warrants it.
Tha'ts my $.02