Hey just read a thread by JeffParish New "Y" Maker Slide End Plates. I believe this is the solution that means I can have the x-carve in sideways but still have the advantages as if the x-carve was in front-ways 
Point is with this adaption I can still use a board 30cm x 70-80cm as it will clear the sides 
Ps, granted I can turn the booth on its side, but would rather not have to go to that extreme