Honestly out of all the books on my shelves, Supertraining easily has the most wear-to-info gained ratio, crossing all genres. That is I've spent more time pouring over Supertraining with the least to show for it out of any book in any genre I've ever read (and I read or listen to audiobooks every day).
I would say 5/3/1 has to be the most reward vs time invested. I started and finished that in one sitting and can easily say that 5/3/1 is one of the major factors behind me breaking through a long-term plateau and hitting a 2x bodyweight raw bench.
Supertraining on the other hand.. not so much. It looks like you've already ordered it but like everything you read, don't be afraid to question the teacher and take everything with a grain of salt. It is certainly not gospel.
I would say CT's book Theory and Application of Modern Strength and Power Methods covers practically every useful aspect presented in Supertraining in a much more presentable and digestible method.
If you want a textbook.. pick up Enoka's Neuromechanics of Human Movement. It will serve you much better in its background knowledge than something like Supertraining.
If you want to be an expert on working around injury (or even getting out of pain), I'd recommend the following books/products:
..in the specific order presented (going through the list in the opposite way will be much harder).