Good find on the library conflict! I don't have any Teensy's here, where space is a concern I use either MINI's, and Pro Micro's cause they're inexpensive.
If you mean those smaller PCB and blue 8x8 matrix modules from eBay, I think they first appeared here:
http://forum.arduino.cc/index.php?topic=143365.0
I have four of them here, just test connected them and they work fine if you edit the MXXX7219 library the same as for the other eBay modules.
Mel