we created this as a discussion forum. so discussion is the primary focus.
we stared this forum because a few of us in the eigenharp community had met on the Eigenlabs forum, which became a bit of a ‘mess’… so we moved to using Google+ groups, which google dropped.
so we needed a new home, one that we had a bit more control of (after moving twice !) , in the meantime, many of us had branched out to other expressive controllers, so we had the idea to expand the scope to help/support/discuss with other musicians.
@David (Gig Performer creator) kindly donated us an instance on their (virtual) servers, which we can administer etc. so I got the domain, setup the forum. and we have been merrily running now for a few years 
so really there are no more ambitions beyond that… as I mentioned elsewhere, we are not trying to (actively) attract new users, or branch out… or be the ‘ultimate’ reference site.
if anything, the idea is to be focused on the niche that we in… to enjoy that.
also its worth remembering, that many of the developers/manufactures in this space are relatively small. so like us (from Eigenharp) they need a discussion forum that is low maintenance, and often ended up on Facebook/Yahoo Groups/KVR etc, but these are not ideal (for things like searching), so polyexpression is a ‘proper forum’ alternative IF any manufacture/dev want to utilise.
tl;dr; polyexpression’s focus is as a discussion forum, and we dont really have the resources to go beyond that. nor, do I want to expand its liability ( by incurring things like hosting fees… and need to fund etc)