Surely, Some ideas from RD were changed to suit CC.
FOR CRYING OUT LOUD! CHRONO CROSS IS NOT A SEQUAL! KATO EVEN STATED IT HIMSELF. It's a new game to like tie in CT and CC, and a bit of RD.
On the point of RD. It's not a dfferent dimension to CC or CT. Up to the point of after Kid meets Magil after the fire, the dimensions split 7 from that point. That is why there are different scenarios all with Kid and Magil. Everything pretty much before the fire happens in CT and CC. Except for a few things which cant be confirmed like FATE, Lynx being a different Lynx, etc. But this may prove that in RD, Lucca's house may have been burned earlier.
And btw, Named like Regonia, Grezenbul etc. may have been prototype names for Termina, Marbalu, the Demi-Humans place etc. It's like theres a guy caled Zoroban or something that's supposed to be Dario, and that guy in the cell, I always prosumed was Radius.
Also, In RD, what they call "Magic" seems to be more elemental. Only by coming in contact with something that can unlock it (like the sunflower), You can't have the CT magic. Acctually, in any time that Serge could use magic, it never succeeded.
And to whoever asked, The Sunflower is only found in one scenario, in the others, Kid doesn't learn magic.