The top soviets often squatted first back in the 70's not sure about Bulgarians, not done for long, but they definitely did it.
At the end of a OL comp how many heavy squats have you done by the time you approach final C & J
How many snatch recoveries have been fought out how many front squats ground out from possibly a dead stop.
Don't see anyone, jr or Ol competitor having pulling technique trouble on their last clean.
Now I assume you mean your back squat is 30kgs above your PC. Your front squat should be better than your squat clean and your squat clean should be say say 115% of your PC.
Your squat needs work, when you head is fresh so you do nice OL style squats (they will not trash you like power squats - well not quite as bad )at the start of your workout. Congrats on working out the answer...