I know many love the Top Jimi VH profiles. With a real cab and power amp they sound good at first, then you hi the low E say with the Chorus rhythm to 'Feel your love tonight' and it farts out with a really wooly low end on the low E string only. I know a real Plexi is not a tight amp but it also does not have anywhere near the compression the TJ adds in there.
Any tricks to dial that out
Interesting. Have you set the definition to 10? Typically that helps in tightening things up a bit.
But for me I just stopped using other profiles after starting to use the JP2C profiles from Choptones. I have never played a real mesa boogie but boy are they tight and focused (especially the Kemper Profiles that I have played).
I'd try the following steps:
1. Amp Definition
2. Low cut at the output settings (I set 80-120 but my room is untreated) or at the profile settings if it's just this one...
3. Green Scream with minimum gain before the amp (or one of the new drives, didn't try yet and don't know how they stack)
4. Throw the profile and find a better one 
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