Welcome to the forums. Always good to have another geezer join the ranks!
Just curious, what weights had your squat and DL gotten to before, on previous programs? You've made 2 20# jumps in each, and plan another 20# jump, which seems like a lot. Of course, if you were squatting 305# and deadlifting 405#, then it's no big deal. But, as you say, "leaving gains on the table" is kind of silly thinking, so there's no hurry to get to the higher weights. Just food for thought.
Looking forward to your future updates,
Bob