Should the resurfacing cut be done with a straight plunge cut ?
Using 1.5 inch bit.
A surfacing pass should be so thin that straight plunge or ramp doesnt really make a difference, however depending on the surfacing bit you may want to use a 20⁰ ramp just to ensure it doesn’t burn up the center of the bit if its a fly cutter with no cutting elements in the center.
I use 0.01" for depth per pass of a surfacing operation.