I'm currently porting the MySensors library to the PIC32 architecture. Specifically, I have a Max 32, which I would like to use as gateway controller with MQTT client. Throw the ENC28J60 on top, and I'll call it a success.
At this time, I have the project compiling, and am currently working through issues on the SoftSPI side of things. The PIC32 has a SoftSPI which makes a few assumptions which don't mesh well with the existing use of a soft SPI library as used in MySensors. Baring that issue, I see little else that is causing grief, so I see no reason not to ask for this to become part of the MySensors project proper at some point.
I've forked the development branch and will track that going forward. At some point, I'll generate an issue ticket and a pull request.