Hay Chris. Not sure if you have seen these for rack tool changers. rapidchangeatc.com/product-category/er20-magazines/ For routers they can make it easy to add rack tool changing but need a slightly interesting macro.
I am not sure i can see how to do a PM but if i remember correctly you are in NZ if so let me know if you are interested in playing as could bring one when i come back down under in a couple of weeks if you have an ER collet machine.