I use two of the hats on the joystick, personally. The castle hat does up/down and select left/right, which the top-left hat does menu left/right.
Additionally, I use the red button on top-right side of the joystick and then the castle hat left/right to pick which UI window to focus on as well.
In addition to that, I have Switch 1 on the throttle mapped to the UI window on the left so that I can quickly get the contacts and nav windows.
As if that isn't already enough, I also have the commands "ship, target station" mapped with voice attack, which automatically opens the left UI window, scrolls to targets, and locks onto the station and then closes the UI window. As well as "ship, request docking clearance" which automatically opens the left UI, selects the station, selects request docking, then closes the UI.
Needless to say, I have a few options
I'm also in the process of building a custom dashboard with modular control panels for Elite, so a lot of the more mundane controls like landing gear, radar range, ship lights, and hyperspace, will be handled by the dash - so i'll be able to free up all my X55 throttle and joystick buttons for more specific use. All Joystick buttons will be about firing weapons and targeting, while all the throttle buttons will be about controlling the various UI screens.