[Koha] Advice for restricting loans from 3M self-check

hi folks does anyone have any advice for restricting some Koha item-types from being circulated (issued/returned) via a 3M self-check machine, but!... still allow the item-type to be circulated via Koha'a staff-admin interface? it seems it might be possible using a specific 'sip_media_type' value for an item-type does anyone else have a similar situation? thanks, Mason