first you create a roof two blocks over the Chorus plant in so that they are only able to spread horizontally. when it creates two Chrous Flowers (a bit away from the place where you planted them) and you mine that one, the other one can pop as well. Of course i cant know wether that is intended or not, but i think you should be able to mine all of the chorus-flowers, as they dont drop, when you destroy the trunk
Cannot reproduce or fixed now. Or maybe I just don't understand the issue. If it still happens, please provide a detailed description of the problem, steps to reproduce it and, if possible, a video. Thank you.