RE: In regard to the custom template question: is there documentation on building such a template?
Sorry, no, their is no documentation on building a template but if you review the code for the Tile Plus template I think you will be able to figure it out fairly easily if your know PHP. I recommend phpStorm, loading Connections and WP as libraries for code completion.
RE: Is it possible to have filters on any fields other than category?
Yes, I do have an advanced search addon available to those who purchase either the pro pack or extension pro pack and request it. It’s not generally available due to it being a little complex to setup, so I do offer setup as a service. If you know shortcode well, it is really not that difficult. I can provide it and instruction if you purchase one of these those bundles.
Hope that helps!