This below is too dangerous, why would someone ever need that? If he is too lazy to rollback all changes, he doesnt need, it is not Riders concern or problem but in case of selecting by mistake a this option will cause to lose a lot of work. Why can you just do it like Visual Studio is doing that "take changes to the new branch" or even "smart checkout" by default. Shelf or Stash and let the user to decide whatever he wants to do with all those changes. Sorry that will cause a lot of mess with the Junior developers and even Seniors can possibly make mistake. Please remove this or improve it more friendly for the developers.
If your local changes are going to be overwritten by checkout, JetBrains Rider displays a list of files that prevent you from checking out the selected branch, and suggests choosing between Force Checkout and Smart Checkout.
If you click Force Checkout, your local uncommitted changes will be overwritten, and you will lose them.