ted, have you looked at this one? i had researched this before because once in awhile i will have a 5 gallon pail with a honey gate on it, that starts to crystallize (primarily during winter months) and it is sort of a pain to heat the pail to kill the crystals.
amazon the almighty..........
Powerblanket BB05GV Bee Blanket Honey Heater, 5 gal Pail Heater with Cutout for Gate Valveit's a fixed temp, and no higher than 110 df, so depending on how advanced the crystallization is would depend on how crystallized the honey is to liquefy. also i am a review person, i read the reviews, questions and answers. like you i am a bit of a seasoned keep with experience on how most of these work, so the blanket is designed for what it is designed to do......
moving crystallized honey to another bucket is a pain, been there done it, that's why i 'cheat' sometimes and strap my bucket heater on higher than it is supposed to go on any bucket, (above the gate) and depending on how full it is. i monitor temp and stir from the bottom up so anything settled on the bottom gets moved up.
not sure, but for 116 bucks i think i might have to try this out.
if anyone knows of anything similiar to this, i'd be interested as well.