I'm swapping out a worn BB and crankset from a late 90s hardtail. I already have a new triple crankset that specs 122.5mm spindle length for proper chainline. However, the frame has a 73mm BB shell width, and these days a 73 x 122.5mm square taper BB is unavailable (sold out).
To maintain chainline, I'm going with a 68 x 120mm square taper BB instead. This will result in the non-drive-side being 2.5mm closer inboard, but I think I can live with that. Is there any drawback to this plan that I might be missing?