Well, there’s no doubt that doing those together would kick your ass. Kicking your ass can be more condusive to bodybuilding than to powerlifting or other strenth sports because of how efficient your CNS is working is so much more important for the latter.
Take the box squat for example. If you were trying to reach a 1RM for the day, you would probably follow a low volume warmup perhaps with a rep progression of 5, 3, 2, 1, 1, 1 or something similiar. If you did 10, 10, 8, 5, 5, 1 the latter workout would be “harder” but you wouldn’t be lifting nearly as much weight on that last attempt because you tired yourself out. Add in a few hill sprints before that attempt and you’ve got one tough workout. But, it’s not going to allow you to express your full potential in that lift because you will not be fresh.
Not to mention, the more fatigued you become, the worse your form ends up being, and your nervous system will remember it that way. With the wrong form that is. Part of the reason that you are doing the lifts are to learn the correct form. Not only could it be harmful to your technical proficiency, but if your lower back is already fatigued, you could just be asking for injury by moving in to deadlifts.
Run a search of Robertson’s “Designer Athletes” article. It includes a heavy squat and heavy deadlift variation in the same workout. Might be more up your alley.
And maxing on bench and then squats is different than squats and deadlifts. Squats and deads work many of the same muscles. It’d be like doing 300 pushups and then going into a ME bench workout. You won’t be able to fully express your levels of strength because of fatigue. Just something to think about.