I like your pros, but I don't see any cons.
You can place a playpen in your attached playroom area for nap time, or you can purchase a baby monitor.
When I started homeschooling my girls were in 1st and 2nd grade. Our school day was 1 to 2 hours per day in the morning with a half hour to an hour in the afternoon for Story of the World. I didn't do much multitasking at that grade level unless is was setting up the next lesson or recording the last subject.