In a way.
When you enter as a Vet dog, or vet handler you drop 4" in your jump height. So by that you are getting the time of the lower height.
As for which heights are getting a time change.
20" dogs are staying exactly the same.
16" dogs got just a smidge extra, mainly to make the YPS number pretty.
And then 12",8" and 4" all got some more time.
Hopefully that makes sense. Your still getting extra time for being a veteran, it's just calculated in a different way.