I have a similar issue, having huge loading times (more than a minute, the game sometimes crash if I don't let it in peace while loading) but quite alright quicksaving ones. I don't think it's related to the MobileObjects file problem as my save is about 2 Mo, and in the "Current game" folder (27 Mo total), the Mobile Objects files is about 2.5 Mo.
It started around the beginning of the Act II I think.
Here are the quicksave I'm using, the system specs and the output log :
https://www.dropbox.com/s/2yyro6nb858e4ap/Data%20PoE.zip?dl=0