there are posts here on the forum about using Blunami. I have never used it.
Hopefully others will chime in for your answers.
The MTH explorer is an entry level system to get people running with their system.
I run MTH's DCS system and have converted other brands to run on my RR. It's tuff for me to help as I've never used the explorer.
I ran DCC in my past, so I know enough to cover the basics.
here's a post that may help.
Smoke unit install with Blunami decoder board | O Gauge Railroading On Line Forum (ogaugerr.com)