Possibly an oedema/edema? Check it out...that is not a disease, but physiological disorder. Other possibility could be a fungal - could be something like powdery mildew or Anthracnose ? Chek for bugs like mealies or scale. I would think oedema...

I appreciate the feedback. My first thought was pest oriented, but I tried to scrape away the mark to see if it was armored/soft scale and not luck, scraping away fully just reveals plant tissue underneath. Some of the larger spots are indented slightly below the otherwise normal leaf surface.

I also considered oedema, however these plants have only been watered twice (i forgot about the little one, it was in a corner. I would've otherwise watered it more regularly) since being brought inside - they are in the classic gritty mix formula and I'd been letting them get rained on and/or watering with a quite high frequency (sometimes twice per week) when they were outside. It's been almost 2.5 months now since they've been in however the marks continue to spread and show up on new growth. I haven't dealt with spider mites very much, so I was wondering if it could be a mild infestation of them as I haven't seen any webbing to show a serious population of them.

I've got these in a south facing room that I run a dehumidifier on low in to keep it a but warmer and drier than the rest of the house. I know hot and dry are generally the conditions spider mites love which is why I suspected them at first. However I haven't found much info on what spider mite damage looks like on succulents in particular. I also wonder if it's some sort of rust fungus or leaf spot. I just feel like I have to narrow it down a bit so I know what treatment options are prudent.