It is not as if the 'I' is an object-symbol (a chosen or imprinted object) appearing within the field of an impersonal witness consciousness so that it can be enlisted to refer to the subject or centre of that field (when taken) as (being) embodied experience. If that were the case then 'I' would be a sort of name, the name of reflexivity. Names however are detachable in ways that I am not. If a request is answered by '[your_name] will do it' that expresses a quite different intention from 'I will do it.' Suffice to say that failure can be shrugged off more easily in the former case. Similarly with making a report: '[your_name] witnessed x' would not be acceptable where 'I witnessed x' was required. You can substitute any other way of designating yourself as some sort of object-like matter,  such as 'this body-mind', or 'this self' or even 'this Dasein'. All such locutions have a slightly repellent quality, as if shirking responsibility. The 'I' exceeds the objective world and cannot be negated away in the same way as every other objectivity.