I saw a small problem when I tested the upload plugin and dashboard site.
So I just created test style to see how site works and i found some small problem there.
When I edited the plugin, and go away for get the package from courier, the site end sesion.
So I didn't know about that, because site didn't show me any message.
I tried to add some Screen's or upload a file, but: failed.
So maybe add some information when the sesion is ended ? It may help.
Other small problem. After deleting the plugin ( edited couple of times ) when I refresh the site I sow that deleted plugin but with another date, like edit date. So i deleted it and problem solved... No.
After loging out from main dashboard site and login again. Then plugin was still there. After deleting and relog plugin gone.
It may be some cache problem, but also it can be some site problem or addon in my chrome.
Idk if that helps anyway, but topic said Suggestions and Feedback. ;)