I wouldn't do it all in one day. I wouldn't do it for all the exercises either.. just the ones you do the most.
For example, on leg day, instead of following the routine exactly, make the first set you do (only of the exercises you want to 1RM for) the one you use to test.
On leg day I did my 1st set was squats and I used this to test my 1rm.
If you rest completely you can use this for other exercise sin your workout as well.
I would just use the first set of each exercise to test your 1rm.. may take a couple workouts to get everything as accurate as possible, but I certainly wouldn't bother with testing a lot of the exercise that you don't do often.
The basic ones are the most efficient and worry about the rest as you do them in a routine.
Its actually very easy to use.. when you do the first set of the first exercise (say squats), pick a challenging weight (or in this case, whatever you can safely lift onto your shoulders) and squat as you normally would until failure. Put the reps you did with the weight you used into the program and it will calculate your 1rm.. it will also tell you what weight you would have to do in order to challege yourself in the rep range you choose