Barry, I was talking PS-32 specific because that was what Charly was working with and what most of the folks doing upgrades have to work with.
Dave, Yes it does make sense because that is how MTH did it. As I explained, MTH by procedure has the parameter data also in the PS-3 Sound Files.
I have upgraded plenty of engines to PS-32. I also have done quite a lot of PS-2 5V repairs with the PS-32 5V board and PS-2 3V conversions to PS-32 so that 2 railers can use DCC. I Have loaded newer PS-3 sound files when they are available. I use the bench tester so I can see the light effects and such.
I also have tried to use the PS-3 flash codes in testing, and it does not work. There are several post where folks upgrading steam made the mistake of loading the PS-3 Flash and Sound file and effectively prevented the engine from having any lights and such. We had to send them the PS-32 flash code again and they reloaded the Flash code and all was well.
My conversations with Jason explained how they kept parameter codes in the PS-3 sound files. There are other details an some early files may not work. Apparently there are toggles in the sound file that tell the processor where to look and some items just won't work right. MTH can correct those SF if needed. Most files do work. G