Maximum cap on restricted categories! bug?

I love your plugin. Its simple and straightforward. Unfortunately I can’t use it! This is because I have a few thousands of categories and I want to assign one custom role I created to be the only one with access to most of them. I do this by clicking on select-all and then un-selecting the few ones available to the rest of the roles. However after the page is sent and reloads the counter of restricted categories for the role is is only 989. If you can extend or remove this max. cap it would be great!

* Incidentally, it would be nice to be able to select all child categories recursively when clicking on the check-box of a parent category.

Thank you sincerely,

https://www.ads-software.com/extend/plugins/restrict-categories/