It exists softwares solutions for advanced gauges displays and functions for X-Plane. FlyThisSim developes one of them : avsimmap II, and informed us of an upgrade.
“Stand-alone avionics Version 1.1.1213 Integrates the X-Plane VORs and HSI’s with our WAAS GPS.”
“That means you get the correct horizontal and vertical deviations, to/from flag and Nav flag when the nav source is set to GPS. The STEC-55X now engages the autopilot correctly for aircraft with and without a flight director.
More details of the product can be found here.
If you want the upgrade, just email email@example.com for the new files”
Eric N. Paton