https://www.reddit.com/r/DestinyTheGame/comments/bqd3if/double_exotic_perks_on_ghost_shells/

I have a Speed Demon ghost that I keep around for Scourge of the Past, so I can use my Vernier Thrusters ghost without having to give up instant summon... but it's annoying to remember to switch back to a Guiding Light ghost the rest of the time (for the extra XP). Now I don't have to.

This is super-useful. Tested and it works.

(I can't, unfortunately, get rid of all of my Hard-Packed shells; as far as I can tell, only the Totem shell is capable of rolling with Guiding Light, Speed Demon, and a planet-specific combo detector... and (after almost a dozen tries) it seems that the only combo detector it can roll with is Tangled Shore, so If I want to be able to find resources and chests on other planets, I gotta keep the Hard-Packed variants... but my desire for random (non-instasummon) sparrows is actually greater than my need for resource detection, so I think it's an acceptable tradeoff.)