This works- but I think you do have to modify the file in preferences-2.json to get any value higher than 300. The "md-slider" object in the admin panel has a max value of 300. You can set the value higher than that by modifying the json value directly.

Sorry this is a duplicate of https://ubooquity.userecho.com/communities/1/topics/1063-issue-with-opds-in-310 

Hi I'm chiming in on this very old thread- the main reason I would love an android reader for comics is for ofline mode.

Ubooquity web is great but doesn't let me read books on planes. An app that lets me flag issues to download to the device for offline reading would be amazing.

The closest thing I've found for this is Challenge Comics Viewer but it is a little slow.