4" from a Marshall stack is silly.
Please search for a recent thread on this forum where the subject of high SPLs and their effect on condenser capsule diaphragm health was discussed.
P.S.: I think the Neumann mics you saw during Jimi's performance at the Isle of Wright Festival in 1970 were more likely first- generation U87s, not U67s:
I just saw a fascinating, must-see documentary for MIles Davis fans called "Miles Electric" - his stellar band's performance preceding Jimi Hendrix's that day.
There were, from what I could see, quite a few U87s on stage (purple badge visible on one shot. The U87 at the time was indistinguishable from U67s because it still had mostly Tuchel connectors with U67-style swivel mounts)
Ominously, lined up at the back of the stage, one could see what was soon to come after Miles's act: several towers of Marshalls...
P.P.S.: One of my dreams, one distant day, would be to compile, with the help of recording and mic afficionados out there, a listing of all seminal performances, studio and stage, and the mics used to record them.
This listing could be formatted in an easy look-up configuration, without any cluttering narrative.