I think unless you want to roll your own form in a code page and use html to hide the save element after it is clicked it is going to be impossible to stop users from spam clicking. I have done this a few times before when it was critical that the user only hit the button once and it wasn't worth training them. To me this is one of those things that falls into user training rather than a software solution but I also get that it seems like companies really don't want to train these days.
It kind of sounds like an internal Quickbase issue anyway. I don't think it should be creating multiple records off of several clicks if the first record has not even saved yet.
