2015 Cannondale SuperSix EVO HiMod - Crack in steerer tube

[ParisCarbon]

Its now my spring bike / travel bike, but doing my pre outside ride maintenance, I had it apart lastnite, and noted a bump on the back side of the fork steerer... running my finger inside the steerer as well, I also notice a small ridge in the same location... and you can see a very small vertical line.. its about 1 cm long Id guess...
Its going to involve lowering the stem now by a cm, and I can deal with that.. but can I "assume" that I can cut that part off (and a few mm below) and remount the stem safely and continue to use it? After the bumps I mentioned it is perfectly smooth, so right now seems to be isolated to just that top area...