Jerry didn't use an EQ with the MXR+. What's interesting is that the MXR is a flat response pedal. It has no midrange voicing or boost, and has fairly full low end. I think that it's the lack of high-end rolloff that makes it sound bright to some people. The Boss pedals, like most overdrive pedals, have a strong midrange EQ to them and part of that voicing is a strong attenuation of the highs. What I hear in the MXR+ is that it is sort of hi-fidelity in that it contains tons of that top end sparkle which can seem like his clean pickup tone is preserved, even with all that MXR dirt/fuzz across it. It's very slicing and knife edged, and in a very cool and Jerry kind of way. Now I also very much dig what he got from his Boss pedals, but they were relatively much warmer pedals and less searing and sizzling. But they made up for it in fatness and uber-sustain and a more "tubey" character. The sharper MXR+ did more precision brain surgery on me, if that makes sense, and I'm guessing it probably does to those who hang out here.
I tend to consider '80 thru '88 a pretty consistent tone era. Rig didn't really change much, and the MIDI wasn't hogging up all the space yet. The lack of intense drug use in the late '80s shows up as more focused delivery of the songs, but overall, the playing and sound is pretty similar to my ear. You can hear it get a bit more sparkly in '82 with the switch from Dual-Sounds to Super II's. One key element to notice in the'80s with the MXR is that you can hear when he flips the switch to kick on the MXR+, suddenly whatever note he had ringing becomes on the verge of feedback. Listen especially to the middle solo of a Stella Blue where he has a lot of space and clearly goes between clean and MXR. Just the sheer loudness makes his guitar tone and string response a lot different than most of us sitting around kicking on an MXR. That feedback level volume creates lots of effortless sustain and a harmonic "bloom" that merely picking a string doesn't tend to do.
... and it's just like any other day that's ever been...