@Rosemary18
I have also blocked some dates twice, but I have ended up to the same conclusion as you, I won't do it again. Not because the guests did something wrong, but because I add an extra difficulty to my work, because I exclude other people that are maybe ready to book and because I there is always the fear of letting my dates empty in the last minute. Also, the most difficult part when you have instant booking is to synchronize your time with the guest, so that you open the dates and he/she makes the booking immediately.
There many listings and many guests for everyone. So, let's keep it simple! (my opinion, of course)