Like the tittle says increase the rates exp not so much but carat definitely some may say that'd make the game boring faster but in hindsight it would actually increase the amount of players coming and staying it doesn't have to be a big increase maybe just something like going from the average 100 carats for top 4 to 200? just a 100% boost would greatly help out the newer players a friend of mine tryed the game out and had 20k by level 15 but the thing is that 20k is all you get then your out on your own going from getting easy carats to trying to grind out another 20k the reason the popular maps are popular is because they take less time to actually play causing an increase in gain over time but with this increase on rates some of the other maps would be played again helping the community learn to spread out on what they play in terms of maps and modes
This has already been proven not to bring more players. Back on OGP it was a struggle just to make carats and getting scammed was like losing a child. Towards the end of OGP they implemented items for gaining more carats and then on GC, they introduced the bonus hours. In no way will increasing the rates again bring anymore players.
When OGP burned the bridges by not letting use do a true transfer, a lot of folks left and never returned. Then RF went to GC, and alot of the popular scrolls/exos in shop were changed to "Timed" item which was a dirty move, drove more off. Not to mention the overhaul of people only wanting to nhaa or play moon makes its boring real quick.