1025r Frt mount snow blower

I'm looking at making a SB purchase sometime in the future and I have to ask this question. The spec's state a 1025/1026 can run a 47" or 54" SB. With knowing that why can't they run a 59"? It's only 5" bigger. From what I have read here, everyone states that their rigs handle the 54" like its nothing and eats snow like crazy. My typical snows will be about 6-8" not the 10-16" some folks might see to where a 59" could be to much but maybe slowing the units travel speed will allow it to handle it.

Any input will be appreciated.