Hi~ 다소의 공백기=(literally this means "some break" because 공백기 means a period of time you spend not doing any work; however 다소의 is not very colloquial, it's more like literary) And for 영화 개봉까지의 공백, 공백 here is a bit awkward just by itself, I think more sentences should be there. For example, 영화개봉후의 공백기간=> this means the period of break after the release of the movie. hope this helps!

I wonder if 사이 is a better word to use for an interval of time.