Before keka, I used to use CleanArchiver. There was a convenient feature in the preferences to archive all the files passed to the application individually. Would be nice to have this feature in keka... (I've included a screenshot of CleanArchiver.)
Sure it can be done. Hope for next release, will send you before to test it
I've made the first attempt to implement this feature.
Here the build:
Note that there's no option to activate or deactivate the feature, it's made by default on this build, so just use it for tests.