Same here, really life changing for me with a back injury. I recommend hex bar deadlifts as they put much less pressure on the lower back than conventional ones. And front squats for the same reason.

Have to disagree there as it doesn't make much sense. The point is to strengthen the muscles of the back. Keeping a more vertical back angle directly reduces force on those muscles while keeping the same spinal compression. You want the opposite, to have maximal muscle involvement with minimal compression. Back extensions progressing to normal deadlifts are indicated.