Many users will agree that both Skritter and the Chrome Zhongwen extension are 必不可少 for maximum efficiency in studying Chinese.
Here are 3 small suggestions for better interoperability. Perhaps other users can find more.
[1] Study mode
[1.1] When hovering an expression with #characters > 1 in study mode, the corresponding word pop-up currently does not show up (only for individual characters). Enabling this could save a lot time for users who need more details. That way you could get to a variety of explanations and example sentences in a second without going the long way (i.e. Skritter word popup).
[1.2] I would also be glad if you could disable grading for shortcuts that include the ALT key (Zhongwen dictionary).
[2] Queue system
Please also take Zhongwen into account when coding the new queue system. Maybe you can ask the developer to attach the source URL to the var string sent to Skritter s. t. we know where an entry comes from.
Link to "Zhongwen": https://chrome.google.com/extensions/detail/kkmlkkjojmombglmlpbpapmhcaljjkde