My succulent is otherwise healthy as far as I'm aware. I don't know whether this is normal and I never noticed it, or whether it's a sign of something more concerning.
My mother-in-law speculated it could be insect bites, but is unsure.
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Sorry for the late answer.
I believe your plant has signs of Oedema. Often caused by over saturated soil during a cool period. It is believed the wall of the plant expands with some of this excess moisture leaving a pimple/blemish. As long as you stop watering so much during periods when the plant is at rest the problem should continue. The blemishes are permanent as long as those leaves are on the plant. They do not cause any harm to the plant. They are small pucks in an otherwise beautiful plant.
This can happen to almost any plant. Some succulents are more prone that others. They tend to slow down their growth during cold periods. A semi-dormant state. During this state the can not use water as efficiently as they would if the weather were warmer. This can happen anytime the plant goes partially dormant. Sometimes it is hard to predict what they weather will hold, like fall and spring.
The only thing you can do is be pro-active, make sure the potting medium you are using is very well draining. Most succulent want about 50-75% drainage matter to brown matter (water holding). Make sure your plants are not packed to close to one another. Make sure there is plenty of ventilation around your plant. Stay on top of weather forecast, will help you planning watering cycles. Do not fertilise your plants in the fall or winter. Only give you plant extra diluted solution in early spring. Once the weather starts to warm consistently you can increase to a normal succulent fertilising dilution.
The following link is written for professional greenhouse growers, but the information is relevant to the home owner as well.