Opening a pps presentation from Impress File-Open menu starts the pps presentation. Yes pps is PowerPoint AutoPlay but opening the presentation from MS PowerPoint under its File-Open menu does not play automatically and it gives users to access to edit/save the PPS in other formats.
In Impress, if you want to copy and edit the file, you should use File Converter Wizard. Most of users does not aware of this. They complain  about not -so said- being able to edit the presentations. Changing file extension manually to PPT is another option but these are not the way as natural and easy-to-guess.
PPS presentations starts directly whether they're opened from File-Open Menu
Having the normal controls like odp as the pps opened under Impress File-Open menu. If all edit controls are not available, a warning dialog may appear to convert the file to ppt/odp to edit.
Operating System: All
Version: 18.104.22.168 release
*** This bug has been marked as a duplicate of bug 45233 ***