I’m not sure I understand what you mean. Addons don’t make interpretations of the G/S data, it is imported into MSFS and presented via the G/S deviation pointer in the same way on all aircraft (instrumentation dependent). We are not referring to the FMC/FMGC data, but the G/S information that is imported directly into the simulator.
I found a previous post that referred to this at a particular airport and a screenshot was provided by Navigraph to demonstrate that everything was working as expected. While the screenshot does depict the aircraft sitting 50ft above the threshold, it can clearly be seen on the PFD that the glide slope pointer is showing a full ‘fly-up’ indication. This confirms that the glide slope signal within the simulator is not intersecting the antenna at either the correct location or correct elevation.