I can understand using it for sport models if one has it already for competition rockets.
I probably spend about $1000 each year on rocket stuff other than motors.
I just can't however see a jig ever being worth about a half-year's rocket budget.
I'll just stick to the tried-and-true TLAR method of a well calibrated eyeball and a steady hand.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !