I understand what you're saying and the idea behind it - but i do think back and forth about starting clamp vs starting knot...
with a starting knot, the tension on your first cross (or first few?) is referenced exactly from the knot
with a starting clamp, the tension on your first cross is referenced exactly from that same point, although this time it's held by a clamp, but the second you move that clamp (from pulling), that "reference" point has changed entirely? doesn't that cause more inconsistency? this would be the only string that would be pulled twice... ? wouldn't a "good" starting knot be more consistent? especially for strings that are more sensitive to tension maintenance/stretch/pre-stretch?