Has anybody run a algorithm in Divepal? It would be interesting to see if there's a difference in +N loading, and if it does indeed, cut into your 2nd dive bottom time.
(Of course it cuts into bottom time. All repetitive diving does.)
But more importantly overall is the fact that getting a computer program to say anything about dive safety is missing some important facts about what it means to be safe. We are not safe because a PC program says we are or because a table says we are.
The only 'safe' profiles are those that are completely tested in both wet and chamber dives, and frankly no one is going to be doing that sort of organized testing anymore. No one did it before PADI, and PADI has turned to computer diving. The people who could do the most research (military and commercial diving) have no particular need to test recreational profiles, because everything they do is either going to be under old rules forever (Navy still has to dive in J-Valves, and OSHA still requires them for OC commercial diving), or going to be done surface supplied.
So the only option now is to look coincidentally collected data, and see it there is anything that can be seen. (But that can never result in a recommendation to do things differently.)
The only actually tested tables were tested with the
presupposition of no reverse profiles both, in a dive and over repetitive dives. As it turns out there was not much reason for that presupposition, but that is not important, except to say that reverse profiles were not tested. If they had been tested, something could be said. Since they were not tested, no amount of looking at incidentally collected data can ever justify discarding the presupposition.
People get bent all the time in undeserved hits, so it is clear that tables (or PC programs) just miss some important facts that no one understands. Since there are unclear factors at work, hammering away with the old theory details is just hammering the old theory details. It is not any closer to actually making testable predictions.
But more importantly, no one is going to be doing that testing anyway.
(Thats said, anyone working as an instructor (not doing it on a weekend, but actually doing it for a living) has done reverse profile dives of all kinds. Then again, most people who get bent dive for a living.)