Stephen, the type of anchor has no impact on the effectiveness of a
fully loaded rode with a kellet. Why? Think about how a kellet works.
A kellet artificially increases the catenary of a partially loaded
rode. That can be useful to decrease swing radius in light to moderate
conditions. It may also assist with setting an anchor on scope too
short for conditions.
All well and good until the wind starts to blow, the rode loads up and
pulls taut, and now the low angle achieved by the initial use of the
kellet returns to the higher angle associated with short scope. At
exactly the time you need maximum effectiveness from your anchor, the
rode is puled bar taut, returning your swing radius to its normal
dimension, and decreasing the effective holding power of your anchor.
A kellet can be useful in certain specific circumstances but to claim
universal effectiveness is foolhardy. When the wind starts to blow I
like to know that my anchor was properly set on the correct scope for
conditions, not set in a way that partially compensates for short
scope. Here's the proof: Have you ever heard of a large commercial
ship or a naval ship relying on a kellet to anchor? Of course not.
How would you like to be in front of a board of inquiry or Court
Martial proceeding explaining why you entrusted your ship to short
scope because you used a kellet on Mic's recommendation.