Tekken 3, apparently it does work with an updated bootloader. I had a go (with an older version) and definitely got further than before which is promising. Why, 2.0 is just over the hill and sure looks like it will be a marvellous journey! Stay tuned!
Please remember that this a prototype device and does likely not reflect what the final hardware will be like. This includes compatibility with games as well.
You can hit up ps-io.com if you have any questions since I am but a mere tester, I do not understand the technology behind this wonderful invention.
PSIO Hardware Version: 1.1
PSIO Software Version: 1.1A – Using a Debug Bootloader.
All tested on an SCPH-5502 with a missing CD deck.