I don't quite get this. Surely you would use a studio DI profile for this and then add an IR. One output could go FoH and the other to a guitar cabinet without IR. Am I missing something? I understood a merged profile to be a DI merged with studio profile to calculate the difference and separate the cab.
I think you are correct. The point of this discussion was to try and find out why D.I. sound + cab&mic portion of the sound does not sound EXACTLY the same as the studio profile as @lonestargtr pointed out in the video I've posted in the begining of this thread. But we're talking very small differences here and mostly things of feel rather than something drastic.