Blue Sea makes quality labeled devices for the like of Lewmar and others. The issue will be when you use the device for extended continuous lifts. The motor will get hot and have increased internal resistance.

Using the smaller capacity breaker will probably leave you with a rush to the breaker location to reset it -- but may extend the life of the motor if you really abuse it.

The actual work (watts or foot-pounds, etc.) that the motor can perform relates to the voltage that you're putting out, too. If you don't run the motor, with the alternator putting out, and the batteries at decent levels, then you increase the internal heat and inefficiency.

Except in very rare cases, I always run the engine to get the anchor retrieved. Our wire size is oversized for the capacity to avoid voltage drop and heat-build-up.

Assuming that you do those things, Neil, then I'd use something closer to the full capacity.