Yes for type 1A, 2B and 3 , yes (2A for 2 weeks). I’ve done that a lot for my bench press, starting a few inches from the chest. Here’s a video of the squat, this is called a Anderson squat:
You can also do it with a front squat grip or a Frankenstein grip.
BUT honestly on the big lifts you shouldn’t go to failure anyway so there should not be any risk doing the regular lifts by yourself. If you decide to use pins try to use the fullest range of motion possible and control the eccentric. The only neurotype that can get overall development from partial movements are Type 1A