Since you guys are good at programing server commands (Like common bank, /lobby, etc.), maybe you should consider an exp server command option. When ON the player earns the boosted x3/x2/x5 exp and when OFF the player earns normal, unaltered exp. By default AKA when you first login, it is set to ON. However typing "/exp" will toggle the exp gain. (You'd likely need to reload the block like with NPC skins.)
I know what you're likely thinking, "Is this guy crazy?" "Who doesn't want boosted exp?" Well, two reasons, one of them being personal. First, for people like me who have never hit level 200, we want to feel like we earned the level cap and not have felt like it was spoon fed to us. When you get several levels during an RT run it gets rediculous. Second is that leveling in PSO, slowly working to Lv 200 is a big part of the fun. Grinding is part of the PSO experience. Each level gained becomes an achievement, something worthy of a "gratz" instead of happening every 5 minutes. Making the boosted exp an option caters to both parties: Those who want it and those who don't. Also, if you're like me, you've lost countless characters and don't mind using the boost to get them back up to where they were in the previous incarnation of the game. Again, the server command would give us the choice.
Now I don't know if this is something that can be programmed, but given how the exp boost works naturally, it is not server driven, but more character driven. (x3 exp for a Lv 142, but x2 for a Lv 183 in the same group) So in theory it may be possible. I know it would likely be a lot of work to program and then incorperate into the server, but at least consider the idea please. Thanks.