More exploring last night with Rig Manager. (I have a ton of profiles). Some of the Marshall profiles do sound like Marshalls. For example, Michael Britt's Marshalls. However, I haven't tried them at gig volume so it's hard to tell for sure.
For a powered Kemper, I'm feeling more a more like saying "profiles don't matter".
What's more important is how it sounds. At our last city monthly jam, everyone was blown away by the sound of my Kemper and this cabinet. It sounded amazing.