No reason why it shouldn´t be.
I have a frankensteinA1200 with an internal cd-rom and two removable 3,5"HDcassetteholders for PC 5,25" drivebays as externals.
I just connected the IDE-cables to the IDEsplitter, then when I saw that there was no place for them to go thru the case I simply removed the motherboard hacksawed a hole behind the pccard-slot.
Then i just connected the drives to the IDE-cables and the 5,25"-drive powerconnectors from my PSU( one i bought of an amigadealer, convertedpc-psu because of the acceleratorcard).
It´s not a pretty sight but it works flawless.
And it has a certain Frankenstein-A1200 charm :-D