I've developed an aftermarket touch-based remote for the dbx 4BX expanders.
After a very long development period, I have finally reached a stage where I'm happy with its operation and battery life (>1 yr), so am now preparing to gear up for quantity manufacture. But so I have an idea of how many to make in the first batch, I'm conducting a 'market survey' via eBay:http://www.ebay.com.au/itm/-/201613356119
In that listing you'll find links to a demonstration video and a draft user manual.
So if you own (or are planning to buy) a 4BX (or two), please respond to my eBay survey.