I have a BX2370, I *think* the wheels are the same as on a BX2680 but check on that.
My spacers are
10% the cost of Bora and have worked great so far. Quality is important to me and I'd buy them again in an instant. The spacer lug nut size is the same socket size as the BX front wheels (smaller than the OEM rear nuts), so I have to be mindful to not use the large socket on the smaller nuts when changing wheels and spacers.
I don't run spacers when I don't need them as it's harder on the axles. I run two sets (4" per side) in the woods because the (rather large) chipper shifts around (a little) on the 3-point, and on hills that's a bit precarious without spacers.
Remember the front axle pivots so do not add spacers up front.