It would help a lot to have a subscribe message for [mtr] in order to bind to objects - similar to pattrstorage. The "bindto attribute" does not work with message sequences like this "bindto 1 s1, bindto 2 s2, bindto 3 s3"

instead you are forced to create messages like "bindto 1 s1 2 s2 3 s3", which leads to a lot of unnecessary patching logic if you have many bindto targets whose names are not readily available as a single list as it happens e.g. with parameters that are contained in multiple instances of bpatchers and you create the scripting name path by [iter] and [sprintf] objects.