Save file size difference

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So as you can see my files are getting bigger and bigger with new edits in the session, but then the save file get smaller. It save suddenly faster, loads faster … but the same edits/mis is there. When save files are getting bigger it take lots of time to save. (when clients are there it’s crappy). But all of a sudden it starts to saves faster, file is smaller , and edits are still there… this is weird …

Anyone ?
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