That won’t work on the MP3DP. It is too wide. you will lose build volume in every direction.
The easiest way to add dual extruders to a prusa style is short bowdens, or even just use the mixing style. 2 steppers on a moving axis isn’t ideal.
The snap style of the current printer is cool because it’s easy but after some time you have to shim it with a layer of tape. The new style will involve fasteners of some style.