I am new to the Verse and just back from my first 'deep for me' voyage into the Black (about half-way to Skull and Crossbones after stops at Epsilon Orionis, New Beginnings station, and CXOU J061705.3+222127 in the Jellyfish Nebula.
I think the trick to a successful DW3, after all the things you pointed out, would be a more diversified event. Not a single destination or route but multiple destinations. Perhaps even destinations that would need to be found. My first gut feel would be, with Fdev's help, some sort of deep space colonization of undiscovered Earth-like worlds.
Event would look something like this:
1) a mass search for NEW undiscovered earth-likes.
2) once found, registering that world for a special deep space colonization beacon
3) localized community goals for supplying specialized quantities and strategic materials for a new deep space outpost.
4) support other discovered deep space earth-likes OR continue the search for more earth-likes for the duration of the event.
5) once event completes open "bubble type / 10 LY" colonization around new deep space colonies.
Just an off-the-cuff idea. Tons of fdev logistics needed and rewards - maybe decals that would have a designation of how many colonies you helped set up (like the Titan stars for AX)