Yeah, but on the effort side, they would be much harder to do in Orbiter than in KSP (multibody physics and non-spherical gravity vs patched conics and spherical gravity) and would also interfere with the realism of many add-ons, like for example NASSP. Just as reminder, not to block this suggestion. If we would do something exactly like that, it would be a lot of work for the community to realize and support it.
So, as negotiation: Would it be OK for you, if we would design something like that:
- A flight plan data format supported within Orbiter, that can be exchanged between different modules
- An API in the VESSEL class to access the associated flight plans for a vessel and modify them, that can be used by MFDs, other vessels and graphical clients
- A visualization standard within the graphical clients, that allows displaying the current flight plan of the focus vessel (or all vessels?) in planetarium mode
- A default plugin for Orbiter, that allows to create new flight plans in a bare-boned way.
- The possibility to use custom, better plugins by the community, including KSP-like or much smarter solutions.
A prototype for 1 & 2 could be done in a framework library outside Orbiter initially. The rest could then follow, once the prototype got accepted to be integrated into Orbiters core.