I haven't seen any other module for that space in any of the other trims. It's always possible,but you may be waiting for other years to come out with alternative options.
I haven't really checked, but do any of the other trims include aux switches like the RHO/TRX? Unless someone provides information to the contrary, I would assume that the RHO would get all 6 aux switches if the trailer reverse steering option wasn't chosen. Here's what mine looks like (TRX, no trailer reverse steering).