Is waste not a completely useless skill?

[Roth_Trailfinder]

40 Durability Synths:

Inner quiet
Steady Hands II
Waste Not I
Hasty Touch
Hasty Touch
Hasty Touch
Hasty Touch

20/40
(I usually Hasty Touch and gamble 50% just to get it 10/40 for MM)

10/40
Master's Mend
SHII
HT
HT
Byregots Blessing
Careful Synthesis II

For 40 durability recipes, although this takes a ton of CP, this is what I do :

Comfort Zone (optional)
Inner Quiet
Steady Hand 2
Waste Not
Hasty Touch x4
Hasty Touch
Manipulation
Steady Hand 2
Waste Not
Hasty Touch x4
"best" Touch
Careful Synthesis 2

If the recipe takes two Careful Synthesis 2 actions, I'll replace that lone Hasty Touch before the Manipulation with Careful Synthesis 2. If it requires 3, then I will use it on a "Normal" or "Poor" condition instead of a Hasty touch within that first set of 4 Hasty Touch.

"Best" Touch refers to whatever I can do to boost the next Touch action : Steady Hand, Ingenuity, Innovation, Great Strides, Byregot's Blessing type of chain.

Not one, but TWO Waste Not actions in one recipe! Quite the useful skill, under the right circumstances.

If I'm doing a recipe that takes several Careful Synthesis 2 actions (say, a friend in the FC wants me to make some 2 star item for him) I'll start off with Comfort zone, Inner Quiet, Waste Not, Careful Synth 2's as needed. This puts me at 60/80 Durability, in the "One synth From Finishing" status and I can concentrate from there on Quality.

[UlricCraft]

Oh I agree!
And of course my play-through of skills was only a rough guide.
Obvious Comfort Zone
Obvious Great Strides B4 Byre.

Control points are usually an issue especially for under-melded/geared situations, but that's essentially the basic principle of how Waste Not is useful.