Unfortunately, those variables are only stored internally, but I can offer you a custom code solution if you would like to get it working immediately for yourself.
If you search for PFD.js in the Starship community folder, then search for the following line...
SimVar.SetSimVarValue("L:var_MdaAlertSound"...
Directly after this line, you can add these two, which will create L:Vars for you to monitor:
SimVar.SetSimVarValue("L:var_StarshipDh_L", "feet", this.decisionHeight_L);
SimVar.SetSimVarValue("L:var_StarshipMda_L", "feet", this.alertAltitude_L);
If you want to also monitor the DH and MDA on the copilot's side, then you can just replace the _L's in those lines with _R's.
I hope that is what you're looking for! Sorry that it requires a little work. I always like to offer immediate solutions for anything I can solve, because there is no sense waiting months for an update in the age of the internet