Hi, I have actually recently tried this program for myself and set an easy 5kg PR for my squat at the end (200kg/441lbs).
I took some inspirations from john Petrizzo's training log
here. And I set it up as a four-day split like this:
week 1: day 1 SQ 3x8@70% day 2 Light SQ 3x8@60%
week 2: day 1 SQ 3x5@80% day 2 Light SQ 3x5@70%
week 3: day 1 SQ 3x2@90% day 2 Light SQ 3x2@80%
If you intend to add 5lbs to your medium and light day 5s each week, they will probably get too close to your heavy 5s at some point. I would be better if you kept the same weight for a whole 3 week cycle and then add 5 lbs to them.
I was also afraid to lose my top end strength by only keeping a high intensity session once every 3 weeks, so I tried the 1@90% for 1 cycle but I found that I didn't need it after all, If anything it only adds fatigue.
Your volume is fine I think, i would keep the 3 sets of 2 though. I haven't tried this method for my deadlift but I think your setup is alright, a little less volume, personnaly I would do something like 1x8@~75% + 1 AMRAP backoff@90% of that --- 1x5@~85% + 1 AMRAP backoff --- 1x2@~95% + 1 AMRAP backoff on heavy days but the sets across approach works too I guess. Your light day deadlift volume is ok too, but if you feel like 5s take too much of a toll on your recovery, you can always try doing 5 speed doubles instead. Good luck, the program gets actually pretty hard, don't hesitate to take 10+ minutes of rest towards the end of a macrocyle