I'm not going to into a lore deep dive on past FF games, or anything just going to spit out the facts and idea itself.
Dragoons in the FF series have generally been seen as Dragon Slayers, and one of their primary abilities to do this was to jump really high with a long pointy stick and stab the giant lizards while either in mid-air or after they landed from their high jumps. The problem with the FF14 Dragoon is that he or she is standing on the ground stabbing things head-on the majority of the time.
My solution is two-fold, whichever one works best to alleviate this issue.
A simple swap of the combo's enders. Swap Full Throttle with High Jump, or jump as the combo ender. Meaning after every 2nd attack the 3rd attack would be one of the aforementioned jumps. The same goes for Chaos Thrust, it swaps with Spineshatter Dive And Dragonfire Dive Coerthan Torment. This means those jumps would become weapon skills, their potency would mimic the effects and potency of the skills they are replacing. While the replaced skills either become abilities that use OGCDs and likely have their potencies increased and new effects for them come up with or they are dropped altogether.
I personally like the idea of dropping the replaced skills if not for no other reason than to reduce button bloat or to free up space for new skills that could come later on. To me, this seems like a no-brainer and should have been the core concept since day one when it came to Dragoon specifically, not necessarily Lancer. This means the combo enders would come roughly all around the same time as they did before, full throttle was lv 26 but now jump is lv 30 so you'd have to wait 4 more levels and a job change to finish the combo, and Spineshatter Dive comes at 45 instead of Chaos Thrust 50.
I'll repeat so no one asks, the additional effects of other Chaos Thrust, Full Throttle, and Coerthan Torment would be inherited by their respective jumps, and the replaced skills could either be reworked as abilities that do something else or in my preferred opinion be dropped altogether.
I could only dream that this is in fact what they had in mind for the rework but I figure I'd run it by the community first.