Macbook freezes every few seconds when monitor input is switched

Solution 1:

This happens on just about every computer when you are adding or subtracting output monitors. I suppose it has to do with how the(in this case internal) GPU processes the new output. 2 extra monitors is also a big feat for a Macbook's GPU!

The only way I am aware of achieving what you want would be through remote desktop. However that has it's own caveats as I'm sure you already know.