5 x :30 on 1:00 rest (then increase volume, keep rest constant)
10 x :30 on 1:00 rest (then reduce rest, keep volume constant)
10 x :30 on :30 rest (then lengthen time and rest, reduce volume)
5 x :40 on 1:20 rest (then increase volume, increase rest)
10 x :40 on 1:20 rest (then decrease volume, reduce rest)
8 x :40 on :40 rest (etc.)
5 x :50 on 1:40 rest
10 x :50 on :50 rest
6 x :50 on :50 rest
5 x 1:00 on 2:00 rest
10 x 1:00 on 2:00 rest
5 x 1:00 on 1:00 rest
These are milestones, yes? Not consecutive workouts. An example from my own recent training, working on my 1A1LPU - I moved to a lower elevation, where I was able to get 2 or 3 singles on long rests on my first workout. I stayed with 2 or 3 singles but tried to do them closer together until I was taking :30-60 rest between and then I went for a double at the next session (which was yesterday), and got it, and even got a second double - mission accomplished! I will stay at this elevation until I'm at around 10 total reps, likely as 3 triples, and maybe even go for set of 4 or 5 reps before I lower the elevation again, and with it, the volume back to 2-3 singles.
So that's what I envision above, e.g., you'll work up as needed to 10 x :30 on 1:00 rest, then you'll start lower the rest and, e.g., maybe you switch to :45 rest, get through 6 holds, and you feel that's all you can do. So you stop for the day, and work on building the volume back up, or you take a long rest, do the rest of the reps, and next time you try :50 rest to see if that works better for you. And so on.
I don't see typos. The 3rd line of each little block is a gradually decreasing number because we started with 10 holds but your goal is only 5, so as they get harder, we drop the number. 10 holds of :30, 8 holds of :40, 6 holds of :50, 5 holds of :60. Give or take, it's 300 seconds worth of holds every time, so the hold time really isn't decreasing, it's just matching the rep count to the overall total's goal.
I'm very happy to continue this conversation here or you can tag me in your log - either is fine, and I think here is actually my preference, at least until you start doing it and then maybe it makes sense to move it.
-S-