@JDRoberts made a tutorial a while back. You can find it here:
I doubt there will be official support for the input contacts for a very long time. The MIMOLite has been around for years, and we haven’t gotten official support yet.
I believe the default configuration for the MIMOLite is to monitor for continuity, not voltage… but give it a try on your amplifier and see if it works. If it doesn’t, you’re going to need to mess with the configuration of the MIMOLite itself.