I mean, if you want the Mark-style liquid lead tone in a lunchbox format, have you considered a Mark-V:25? It won’t do as well as your Marshall rack at traditional Marshall “crunch” sounds (though, the Crunch mode on Ch1 will get you in the rough general ballpark, though using that as your rhythm gain sound means not having a footswitchable clean), but you’ll get the full range of “heavy” Mesa Mark sounds out of Ch. 2. And, it’s a small 25-watt head, switchable down to 5 watts per channel, and for a Mesa at least it’s fairly affordable.
There’s always its big brother, the Mark V, of course, and the Edge mode on Ch. 2 probably gets more marshally than Crunch (here on Ch. 2, not Ch 1, while all the gain sounds on Ch.2 on the lower wattage amps are on a 3rd channel). It’s less affordable (though they’ve been around long enough that they’re available on the secondhand market at decent prices, especially after Mesa introduced the JP2C) and much higher output, but each channel has a 90/45/10 watt switch and I’ve had no problems getting good sounds out of mine at bedroom volumes.
My experience though has been if you’re after that Mark-style thick saturated liquid lead sound, your options are either a Mesa, or a good modeler. Not too many other amps really do that.