I’m in 8.5 boots and finally explored some wider boards this year. Starting with the K2 special effects with a 280 waist, which really changed my perspective. It’s great in fresh pow, but I wouldn’t ride it in hard snow. My ankles do get tired and you really notice the width on a long toeside traverse.
My Stranda Shorty is 260, which is a good size for me… not too slow edge to edge and no drag on packed groomers. But I’ll go for my Stalefish with 265 when it gets soft. It’s really fun carving in soft snow, and it made me realize how much drag I had with the typical 252 waist. I wasn’t booting out, but man the drag!
But waist isn’t everything… nose width, taper, setback, profile, they all play a part.
You’re boots are about 15mm larger than mine, so a 258 is still relatively narrow.