Again, increasing staff beyond the MINIMUM required to operate a ride will not increase throughput. Yes, obviously it would if say Disney were only operating half the ride - and so additional staff would be needed to operate the other half - but in all my years of going to Disney, I have NEVER seen them only operate half (or a portion) of a ride. Demand is just never low enough for that consideration. Maybe it was during the few weeks right after reopening, but it certainly will never be a possibility under normal operating conditions - or even near normal operating conditions. It certainly was NOT a consideration when we were at the parks last week.
The idea they're doing staff balancing for ride optimization is nonsense.
If anything, the PPRS has much more to do with staff balancing for all the other stuff. Staffing at the larger shops, restaurants, and the big one: bus transportation. Apparently they're having issues getting the 'formula' correct for timely transportation between the resorts and parks - and this is likely a staffing issue. When we were there, if the Skyliner was working (another story), it was God's gift to the Disney park-goer; if not, and you were left in the hands of the bus system, good luck on getting anywhere in a timely fashion. When we checked in, we asked our bellboy how much time should be allocated to getting to our destination on the bus system - and he said that previously they'd been telling people to plan on one hour - now they've been instructed to tell people 1.5 HOURS. And sure enough, on several instances the bus just never showed - and it was Uber/Lyft/Taxi time.
But there is another reason why Disney REALLY loves the PPRS: you MUST buy your tickets early (assuming no AP), and therefore Disney gets to book the revenue early. And there are no refunds for changed plans or cancellations - they got your money. Now if you don't use the ticket, Disney will honor it later on - but they still got your money early.
The PPRS stinks - and even the CM's know it (talked with several of them about it). It's one more thing to suck the magic out of your Disney trip.