I'm aware that this has been suggested a number of times before. However, I have never observed much follow up to the topic. I think it would be a very welcome feature to be able to toggle parachutes out of staging entirely, like you can with decouplers (as of a few patches ago, anyways). The first and perhaps most significant advantage to this is that it would allow the user a lot more freedom in designing emergency systems for their rocket.
At the moment, I find it very frustrating that although the game includes both an emergency escape tower as well as a dedicated "abort" action group assignment, it's kind of inconvenient and annoying to actually utilize them. The primary reason for this is that they just add additional components to wrangle in staging. The interface could be exactly the same as the staging toggle for decouplers. Just right click the parachute, then click the option to disable it in staging.
Another use of such a feature would be more precise control of parachutes for specific situations. Slowing a landing space-plane, for example. You could have parachutes be in their own separate stage, but then you have to worry constantly about accidentally triggering them at a bad time. With them toggled out of staging entirely, you can decide exactly if and when the parachutes are deployed. On a personal note, my neigh-pathological fear of messing up chute staging is why I've never tried making a space-plane styled after the space shuttle.
A secondary suggestion, for the same reason, is to make it possible to toggle engines out of staging as well.