Why not version archive sharing a separate folder for them, then we download them to play separatelly in itch's own App or HTML5 browsers like Edge?
We could just download it, replace the game file in Itch App or run it inside any HTML5 browser / Emulator to play it (Like Microsoft Edge browser, Google Chrome, Firefox, Etc both in PC and Mobile as all browsers run HTML5. I also tried Other apps like Joyplay and it works well all options keeping saves running directly from the file!). You can try to put it in a Google Drive, edit its access to be only acessable with the link, then share the link for us in the game description to play the versions in .html!