I can help
What depth and span are you looking for?
In general, the webs of the engineered lumber I-Joists are made of OSB.
There are numerous APA publications that reference using plywood as a web material, but I do now think that is happening any longer.
What is your need to have plywood webs? Are these going to be exposed to weather?
I can do a bit of research for you today and let you know what I find.
There are approximately 9 manufacturers of I-Joists that I can research.
Let me know if you would like to do some more in depth research for you on this subject.