Maybe most tend to not often modify their books, and as such don’t mind the creation of cache and so forth that happens only once per book. For me, with commercial EPUBs too I often fix formatting and typos not necessarily all at once in an editor, but whenever I find them as I read. An example, one I haven’t looked at in a while but am getting back to, a work not well proofed and not well made, hundreds of unique typos, many in transliterated Sanskrit. Finding them is constant, and each time a reload recreates the cache and takes 8+ seconds due to images. Not fun.
