HITL simulation

Why the HITL simulation is not maintained?
It is no more supported for copters, but even for planes the official page in the site has instructions that are 4 years old, and mostly not relevant.

We found SITL to be more generally useful.

That being said, we’ve recently had cause to wish we had this back, so it
might make a comeback in some guise.

Any sign of HIL? we need it for testing new aircraft designs in X-Plane