Yeah, I don't think that at this point there is any reason for the thought of collapse to be entering you mind
And if you did actual 20 reppers which are "breathing squats" meaning much heavier than your actual 20 rep maximum..you would be one hurtin puppy. Way overkill.
But it's always best to concentrate of what you can do. And there are many many options. If you don't feel comfortable doing back squats until you get your safety gear in place, don't worry about it. But if you want to do them you should be able to do them fairly safely.