I did my solo class about a month before I did cavern/intro to cave. The instructor is cave trained himself and knew the other student and I were going onto tech training. He strung cave mine all around the big suspended platform at Gilboa Quarry in OH. You had to take your mask off and hold onto the line will you followed it around. Your other hand had to be held up to protect your head. That gave me a huge confidence boost when I had the mask off exercise in my cave class. Another friend took his solo class after he had already done cavern/intro to cave. He said it was almost a nothing burger since he already had all those skills in cave class. I did my solo class sidemount with LP50s. I only dive SM when diving OC.