I was thinking about this, too, and I think it might actually be an issue. Typical ramps and helixes are in the order of 5-10 deg steep (full horizontal speed milling as you have suggested), whereas a tag is typically 45 or more and must be done much more carefully. Better yet would be to use ramping on the tags as well. That way, they could be 90 deg steep. The reason to go lower, in my thinking, is that mill tools don't plunge well. However, 10 deg steep tags would come out much too wide. Maybe we have a chance to end up with a much better tag dressup here?
/Chris