Grind. Find a spot where you can kill lots of guys fast, and keep doing that. Maximize your XP/hour. The most efficient way to gain CP is grinding, with or without enlightenment. If it is not worth your time to grind without enlightenment, then don't, but it is NOT the most efficient way to log off and wait for it to come back.
If you can consistently grind 400k xp/hour, then grinding 24 hours a day would require 133 days to get full CP's. (Hours invested = 3200)
If you can consistently grind 400k xp/hour, but only when you have enlightenment, it would require 900 days to get full CP at 1 hour per day. (Hours invested = 900)
If you can consistently grind 200k xp/hour, but only when you have enlightenment, it would require 900 days to get full CP at 2 hours per day. (Hours invested = 1800)
If you found a better spot with 500 xp/hour, grinding 24/7, 109 days to get full CP. (Hours invested = 2618)
If you found a technique that is fun, but rewards 200 xp / hour, 24/7 grinding would require 240 days. (Hours invested = 5760)
If you PvP, and you get 50k per hour (is this even right? it might be like 50k / 5 hours for people... idk) it would take 600 days pvping at 50k an hour 24/7. (Hours invested = 14400)
See the problem? Although the enlightenment system rewards casuals more so than people who can play more, if you have the mechanical fortitude to grind out xp as much as possible, you will be the most efficient. The source of xp is "only" relevant to your enjoyment of the game.
Buff xp gain for everything.. Or an idea that might offset grinders is a diminishing return somehow. If it were to lower the grind xp by 90% after 10 mins of grinding, then pvp, or other sources become competitive. This would need to be coupled with a reduced xp/CP system and a reduced xp/VR system.. otherwise... ugh, it would take very long to level up.... (but they are ridding us of the VR system sometime too....)
CP is just an indicator of mechanics that need to be balanced