I've got a model-driven app that is currently already in production, and the users are looking for some improvements to the dropdown selection of record owner assignment. I saw a lot of recommendations around the web suggesting configuring a view for filtering what owners show up, but this particular field doesn't have the option to filter by a view. Possibly because some limitations on my org's User table? I'm not 100% sure.
My available options:

So, I've had to start building component for making customizations. I've managed to filter the User list that appears using Javascript that runs during OnLoad that filters by the Team the users are in, so that the users only have to see other users that have access to the app (I've attached that javascript as a .txt in case anyone is interested).
What I haven't been able to do yet is filter out the Results from: Teams
Worse, the drop-down for ownerid shows the Teams at the top, so even though my filter is working, there's enough system groups existing in my org that the relevant users are all buried at the bottom.
Is there a way I can also hide Teams from appearing in this list? A function to also run OnLoad perhaps to just filter them out? The javascript I'm already running build a View for the ownerid (Case Worker Assigned) field, but that view doesn't seem to be the only view that the ownerid lookup field pulls from. I'm open to just running a filter on the Teams list too to reduce it to zero.