In my tests:
di" does work.
di' does work.
dfx does work.
dtx does work.
I’m on 0.8.2, but I remember these working in 0.8.1 I think.
di[ or any other brackets, does not seem to work yet.
For di' or di" are you using smart quotes? ‘smart’ instead of 'regular'. I don’t think deleting inside smart quotes works. It doesn’t work for me.