Stop in for a cup of coffee

Also found this,

LENOX MetalMax

Thinking I'll just run a 4 inch blade and be done.
For metal blades like that the 4 should be nearly as good as 4.5, as long as the cutting edge is far enough out from the tool to be effective. It does reduce your depth of cut by 1/4 inch. But unless a lot of contour, that likely won't matter for sheet metal. For wearing abrasive discs, that would be like putting a half worn one on to start.