Default Odd conflict with navbar

I've mapped 'double-tap home' as menu in GravityBox, and would like to remove the 3-dot menu button in Exdialer. Technically I think it a simple navbar, as removing navbar (via build.prop/UDN/GravityBox, etc) works fine in getting rid of it, but then 'double-tap home' no longer works.

My remappings for double-tap back, longpress home, and longpress back all work fine, and if I map Menu to one of those I can access menu, but double-tap home no longer work for anything until I restore the navbar. Any ideas on what might be causing this conflict.