Milling and polish is fine, but I'm sure you know the saying about "polishing a turd".
A nice surgical steel blade will only last a few days of heavy use, but they are razor sharp, cheap as dirt and ideal for a box cutter style knife. Splurging on x-acto would be a waste of money. An x-acto is about $2 a blade, a surgical is only a few cents a blade. Both lose their edge fairly quick, surgical starts sharper and is like an x-acto after it's been dulled. Neither will cope with heavy use.
Any one who's familiar with surgical implements would know they are designed to work well, not for long endurance.