Another idea would be to let the survey creator know the current length/time to complete the survey, and if it's getting too long, show them advice on how to make it shorter, and show them that they will lose participants otherwise.
3-2-1 steps to go is more engaging than step 1-2-3.
Same goes for a progress bar that says the percent remaining instead of the percent complete.
Would be awesome to be able to customize this in a way that looks natural.
I will also see if I can check out the repo to see if contributions are a possibility from my end :)