I`m not sure what you mean. Shirley it must emulate the custom chips or else Workbench wouldn't work on it...
AFAIK it uses RTG and RTA to circumvent the need for custom hardware emulation to run the OS.
On topic: I never used Amiga Forever. For me that is only the way to legally buy the roms to use with the emulation if you don't actually have the hardware. I don't know if it offers an updated Workbench like AmiKit
AmiKit just didn't feel Amiga like to me so I don't use it anymore.
