Your size isn't made
Most size runs end around EU 46 or 47, sometimes earlier in the styles you actually want. Above that the choice shrinks to trainers, specialist big-size shops, or importing and hoping. The pair you liked is rarely the pair that comes in your size.
There is no size run to fall off the end of. Your last is carved to your measured length, and the Vibram outsole is cut by hand to its outline rather than pressed in a mould made for a fixed set of sizes. Every style in the range is open to you.