Shane,
1) Reassign this LED in the configurator (I have corrected it in the B58 map).
2) SimVimX plugin functions for all radios are programmed independently on any aircraft model, and have all needed functionality (including HOLD).
That means, if you make the real DME (Using LCD / 7-segment indicators and switches), you will get the device working exactly as in real-life instrument, you don't need to even have this device in the virtual panel.
All you need is is do not look at on-screen device.
Also, of course this full functionality is implemented in the SimVimPanel program, and if you are using our panel for Baron 58, you will see all functions working.
You can see how it should work (both in SimVimPanel and in the hardware device) on this page:
https://simvim.com/svp_radio.html
To see demo - click the DME on the second picture, then select the KDI 572/573 device, and then "turn it on", click all zones to see how it should work in your hardware device or SimVimPanel.
(Try to click everywhere, including the "No station signal", No accurate calc")
Vlad