I can't add much to above.
I have found a greater chance of pedal strike but it is pretty minor. It's not only the corners but the occasional short high bumps. You also have to remain aware of curbs that you might otherwise take closer as your stoker may not raise their pedal to avoid a strike. Overall, a little extra thought but nothing requiring post-secondary education to master.
You do need a signal to let the stoker know they need to ease up or stop, verbal or non-verbal. This is needed for pacelining, approaching stops, shifting gears, etc.
They are simpler to mount with child stoker kits. You remove the stoker crankset and hook the stokid to the jack gear. Very clean looking and you don't have to worry about the stoker crankarms. You can even give the stokid (stoker too) a different chainring to give them a different ratio than you. I.e., you can keep a higher cadence and they can keep a lower cadence or vice versa.