Downloaded the feature/backup_repo from github and that works better, everything imported and the list persists upon restart. For a little bit it worked fine and then started having some occasional issues again. The read chapters will occasionally revert on restart back to unread, during a session the unread notification icon will not always update as items are read or as new items appear (right after restart new unread manga will cause the unread number to increase but anything found once the browser is running will not). This is essentially the problem I was initially having which caused me to uninstall in the first place, but is not as bad and worlds better than the list not importing at all. Also the problems seems to occur much more often (but not exclusively) when the browser is under load (either many pages or otherwise using a significant amount of memory) or if the browser is closed quickly after a change to AMR was made (e.g. manually mark a chapter as read and then close the browser shortly after upon restart the marked entry will still show as new). Only really been testing for a day and a half though.
Also I used notepad to edit the list in half to 264 entries and that seems to work fine with v1.5.4. Did a clean reinstall of chrome and the stable version to get the info you asked for, not sure how useful it'll be considering the problems seem to be lessened on the github version you all are working on.
This is the manga list AMR exports
https://docs.google.com/file/d/0B1xSV8E ... sp=sharing.
This is a copy of the errors section of the console after importing
https://docs.google.com/file/d/0B1xSV8E ... sp=sharing.
This is a copy of the errors section of the console otherwise, i.e. after fresh install, after restarting chrome and the list clears, after using a shorter list and having it remain functional
https://docs.google.com/file/d/0B1xSV8E ... sp=sharing.