Sorry, but the FantomG has that problem just as much as any other keyboard. You have to set up the Tones you want to change in advance so that they don't exceed the number of insert effects, and you don't get the buffer reset glitch that affects most older keyboards. You can do exactly the same thing on your arranger, by programming the voices and registrations to NOT switch between different types of insert and buss FX as you change between them. No voodoo, just plain common sense...

It helps, when creating a collection of registrations or Tones that you are going to play altogether, to pick ONE common reverb type, one common chorus type, and if you use insert FX, to try and either avoid those altogether, or pick just one for them all to share. That will make any changes you make totally glitch-free and seamless. The FantomG simply has so MANY insert FX that it is possible to do this in a more complex fashion, but it isn't by any means limitless...