Long story short. Current gravidar is an improvement in the right direction, but would be great to bring tools to flightsim level.
Short version:
* Would be nice to have minimap visible in addition to gravidar.
* Would be nice to have HUD/heading/Horizon visible as overlay.
Long version:
In X-Plane 11/12, normally while flying something like cessna, the instruments are often configured like this:

Aviation "horizon" on the left, map on the right. "Horizon" is this:

in X4 it could be done this way:

On military planes, Horizon and notches are either projected into the helmet, or onto glass pane infrton of the pilot. You can see it in VTOL VR.
And here's Elite HUD for the reference:

Reasoning:
Orientation in space right now is not instantly visible at the glance. The important values are heading (relative to the North), yaw and roll. Ideally a pilot should be able to navigate through sector without ever switching anything.
Current changes in gravidar improved the situation a great deal, compared to previous version. Right now I can mostly align myself to the sector plane, aim "north"/"south"/"east"/"west" (reltive to the sector) without going to the map. Which is good. However while things improved ,this is a bit imprecise. I still need to eyeball axis widget, and can end up 5 degrees or so off the intended direction. For example, when looking NE direction, aligning to the plane becomes harder.
So, alignment problem can be addressed by making traditional aviation hud. Heading at the top witch notches which indicates yaw, Then wireframe horizon which indicates both roll and pitch.
A possible idea is that this doesn't have to be installed on every ship. For examle, wireframe hud could be present only on military vessels and could be missing from civilian ones. It is even possible to make race-specific version, but that is resource intensive. And generally not necessry.
In ddition to "in which direction am I flying" another important question is "where I am" and "whaat's nearby". That's minimap. Currently coordinate display is disabled, and switching to minimap requires me to cycle through 3 or 4 radar modes. So would be nice if it was possible to keep both minimap and radar visible simultanoeously.
That's the rough idea of it.