This is an interesting point, but I think I could see it going both ways. On the one hand what you're saying makes logical sense. The time between P positions is reduced for a slower swinger, so that golfer might want to apply forces later to give them the same amount of time to propagate.
On the other hand, you could probably convince me that forces propagate faster for a faster swing. When I think about doing a motion like this at a slower speed it feels like maybe everything just gets stretched out, but that forces are still applied at the same position.
I feel like the best data point here would be to compare peak force for LPGA vs PGA pros. Both sets should have reaasonably optimized timings, but at noticeable different speeds. If the absolute timing side is right I'd expect the LPGA players to peak later in terms of P position, and if the relative timing side is then they should peak at the same time. You might even have that data, I'm not sure.