All three games supports rendering in resolutions higher than 16:9 already but do not correct the picture and becomes stretched across the screen, leaving a distorted game for ultrawide users.
Flawless Widescreen already exists to help with this yes, but I feel something like this integrated into the hook would be more future proof, better, maybe allow more finer control, and better compatibility as I think Flawless Widescreen only supports specific versions.