I have not tried bleaching kallitypes with Ferri, but since no one has jumped in to answer your question I'll throw in what I have read.
According to Stevens book, yes, you can bleach with a Ferri/bromide bleach. You will need to use it very very dilute since the silver is exposed on the surface of the paper. You can also do indirect toning with kallitype and bleach & redevelop in a sulphide toner. Also selenium toner can act like a bleach. Maybe it would be possible to use a weak farmers reducer to locally bleach. Plain fixer also beaches kallitype.
This really would be unconventional with kallitype and they tone beautifully in pt, pd & gold prior to fixing.
I will be printing kallitypes this week. If you want I can make a couple of small prints for you to experiment on. Just send me a PM