As far as I can tell, the OOTB behaviour for an N:N subgrid seems to be to ignore what you tell it in terms of default view, whether to turn on the view selector, etc... and just use the Lookup View and have the View Selector on for all views. I found some Javascript (https://www.magnetismsolutions.com/blog/paulnieuwelaar/2016/06/20/filter-n-n-add-existing-lookup-dynamics-crm-2016-turbo-forms) to do a custom filter for an N:N subgrid, but that's not exactly what I want to do. I want to do what the control implies it can do and use an existing view. (I don't want to hardcode the fetch like in the link, because we already have a view set up for it, and if we change the view I don't want to have to change the fetch as well.) I tried the setDefaultView function as a long shot, but it doesn't recognize either the relationship name or the subgrid name for the "control" parameter.
Is there any way to do this?
BTW, if you'd like this to work OOTB (or at least not have a control that pretends to work when it doesn't), I submitted it at the Ideas site here: https://experience.dynamics.com/ideas/idea/?ideaid=a66bcd94-244f-e811-bd6d-0003ff68b41d
