Almost two years ago I wrote part 1 here: https://vimvq1987.com/speed-catalog-entries-indexing/ on how to speed up your catalog indexing performance. If you have a fairly big catalog with frequent changes, it might take longer time than necessary to build the index incrementally. (Rebuild index, in other hands, just delete everything and rebuild from scratch, so it is not affected by the long queue in ApplicationLog). I have seen some cases where rebuilding the entire index, is actually faster than waiting for it to build incrementally. The tip in previous blog post should work very well if you are using anything lower than Commerce 11.6, but that is no longer the case!