Accessory Dwelling Unit (ADU) that we lease to a long-term tenant on a month-to-month basis for $2,850 per month (inclusive of all utilities), and a 300 sqft.

Thank you Alan, I was looking for a real sunlight or option to bring in sunlight with a mirror or any other accessories that’s on the market.still appreciated your list of lights. 

You'd most likely have to look for a commercial unit, which would be more likely to have the card reading accessories you're talking about + they can keep up with the constant use, which residential units aren't designed for.

The ordinance may require a permit to be obtained for the creation of a junior accessory dwelling unit, and shall do all of the following:(1) Limit the number of junior accessory dwelling units to one per residential lot zoned for single-family residences with a single-family residence built, or proposed to be built, on the lot.(2) Require owner-occupancy in the single-family residence in which the junior accessory dwelling unit will be permitted.

Is an ADU (accessory dwelling unit) in option for your home?

See screenshot below from https://bouldercolorado.gov/services/accessory-dwelling-units. 

I'm seeking insights into the pros and cons of investing in Accessory Dwelling Units (ADU) in south bay versus buying a condo in east bay, particularly in terms of appreciation and cash flow.

I was informed that Accessory Apartments for a member of the family was permitted, and that they have to be located within the dwelling. 

Pg. 31 pertains to Limited Use Accessory Dwelling Units. 

The Orlando area also has some interesting properties with accessory dwelling units (ADU) such as guest house, pool house, separate in-law suite etc...