you can just ctrl+alt+click on edge and it selects all parallel edges in a loop.
But back to the knife tool.
It already have a huge list of modal keys, and without refactoring a UI, there is place for only one additional key
just look at this list, it’s already hard to search a proper key for your action…
So we need a checkbox somewhere in the properties - interface to see modal keys on screen in the corner of 3dView or as default under, something like this