What about scaling UM2 Z stage?

What about scaling UM2 Z stage? Stock variant is 4mm plate ( MIC6?) and two flange linear bearins LM12LUU - 57mm long. So the base is 57mm for 200x200mm. For 400x400 bed we can double base using a pair of bearings for each Z rod and some rigit frame for bed. It makes the whole printer taller for about 10cm but more simple.