Filtering and column editing for Many2Many attributes


I have 2 questions please:

1) During editing form in the SMAX Studio is possible to set visible columns for related records in 1:M Grid relations (pintscreen 1) e.g. for Requests. These added relations are type "MultiReadEntity". Why is not possible to set visible columns for M:M Grid Relations with type "MultiEntityPicker" (printscreen 2)

2) For both added types of relations into the form is visible symbol for filter, but I can set only as a administrator while editing specific request. Is it please somehow possible to set general filter (to set which related records will be available)?

Thank you very much for advices