@jameslo pd.exe and pd.com seem to work the same for multiple instances.
They open the wish program as they are started.
I always use pd.com loaded by a batch file for my live shows with Asio4All for some reason that I can no longer remember.
(That's a bit frightening....... sometimes I fall over my posts from only a year ago and I don't remember even knowing the information I posted!)
The Asio4All driver remembers it's settings for executables that call it, so that they can be different for each program.
Maybe once the hook is into one pd.exe the 2nd instance is ignored.
Maybe try one pd.exe and one pd.com in the batch file?
Two instances of wish.exe are also opened, and the ports automatically adjusted
I will have to open my suitcase and dig out some asio devices.
Messaging is easy between the two instances.
Audio could be streamed between the two instances through the net library [udpsend~] and [udpreceive~] that work well over a local network with a bigger block size and should be perfect on the same computer with a blocksize of 64..... ?.... hopeful maybe?..... that is the possible stumbling block (pun) that needs thoroughly testing.....