We use monologo style custom icons for our preconfigured LTI tools. We would like for them to be filtered just like all the other activity icons so they have the same style.

You can add the `filtericon` parameter to custom icon URLs of preconfigured LTI tools. Then icons of activities created from this preconfigured tool will be filtered as expected when seeing them on the course page or when viewing the activity's page. But they don't get filtered in the activity chooser. The reason for that is this condition. My suggestion is to also filter custom LTI icons if they contain the `filtericon` parameter in their URL.