BTW, if we are trying to define a new version of Games Cavers Play, I'd expect that Cheryl is right that bouncing an outdoor pit is common (I've done that, too, although they've been <100 foot jobs...most in the 35-50 foot range).
Doing a pit as part of a longer trip through a cave certainly adds a degree of difficulty.
Doing a complex, multi-drop cave solo is yet another degree of difficulty.
Having someone "in the cave at the same time" is irrelevant unless those people travel along with the "soloist" and/or appear at key points in the trip to give advice or help while the soloist is in the cave. This could range from leaving their rigging for the soloist to providing light or whatever to speed the soloist along. At that point, I think the game is somewhat different and diluted.
Leaving behind a team at the entrance or having a call-out to a friend or family member should not DQ the solo. But if anyone accompanies the soloist through the cave, I think the concept has been bent a bit too far to be called a "solo".
What about a soloist who goes into a cave, rigs a pit and comes back; then returns next day to drop the pit solo and then does yet another drop farther along? Does the break in the trip in any way change the game?
What if his wife tells him she'll kill him if he ever does it again and he survives the solo only to face an enraged spouse?