My impression was that the only reason that the toning was done before the fix was due to the fading of the image in the kallitype. Since this fading does not occur in a silver print, the sequence might not be an issue.
After the Kallitype is developed, it's cleared, and then toned, right? So what happens to a Kallitype if the toning is done with all the uncleared sliver still in the paper? Does the toner start to work on the uncleared silver also?
I'm thinking that since a silver print is not cleared until the fixer removes the silver, then there may be problems with staining associated with the uncleared silver in the paper.
Sounds like a fun experiment.