Please allow for injecting a delay before redirecting to a new URL (internal or external) when submitting a form.
EXAMPLE
When a user submits a form, depending on the network/browser/etc, the URL change might be happening too fast, before the onsite tracking pixels have had a chance to fire.
Allowing for adding an (optional!) delay between submit and redirect will raise the chance of various tracking scripts to fire and with a good, thought-through (built-in) animation in place, it will not affect the users’ experience.
It could be something as simple as this (made nicer looking of course, but just to convey my thoughts in a visual):
