That's some pretty bad sciatica.
I've noticed a few things that probably ain't helping.
I noticed, for instance, that you do precor squats 'because that works for you' due to lower back issues. Plus lots of leg presses. I don't see any stability. I don't see much that promotes mobility where you need it. So let me ask, in the words of Dr. Phil, when it comes to your chronic back problems, how's that workin for ya?
You may want to include some piriformis stretching in your pre or post workout regimin. Just in case that has some relationship. It won't hurt and could help.
I would urge you to let go of the nation that fixed plane of motion squats and open chain leg movements are somehow "protecting" your back, because the opposite is usually true.