Pit limits (penalties for overspeeding etc.) definitely do work with "black only", yellow flags work (just not full course yellow), and blue flags still work. (It just won't give a live penalty I think, but you'd get one anyway after the race for impeding etc. via incident reports.)
Also, typing is a little bit different to pushing 2 buttons to control your pit LCD.
Also, typing is a little bit different to pushing 2 buttons to control your pit LCD.