An interesting experience I had was deciding to enter my novel into a contest, and discovering the contest had strict requirements on how long each chapter had to be. They could have set a total word count requirement but instead they wanted X chapters of Y-Z total words.
It was interesting to re-edit my novel to fit this format because in some cases, it created this awful impetus to 'pad out' key moments or the flow of the plot in order to hit the Y mark, and in other cases I had 'too much' and might need to cut an interesting moment short or trivialize what someone was saying to fit it all into a 'chapter'.
Where before, I had just written more or less how much I thought needed to be on the page, which meant I had some chapters that were 500 words long and some that were 2000 words long.
In the end I think it improved the work in a few places just through the process of being edited again (for the 10th or 11th time - try writing a novel sometime, that part is fun, editing it all over and over is the hard part), but overall having new conventions enforced on it was just a lot of busywork, and the work breathed much better when allowed to be concise at the right moments and verbose at others.
A good lesson for me in terms of 'not all constraints are useful ones', since I'm used to thinking of constraints as something that enables creativity and productivity.