From what you have written it appears you are more concerned about making appearances if this person was a technical partner, rather than any technical issues.
There is a really good question Should I add people before looking for funding with several good answers that talks about the need to have extra people on your team when making appearances.
Other than that it sounds like you already have a good relationship. You need to decide exactly what you are looking for in a partner and if it is important for someone to show up when you are making your pitch or for some other appearances.
If everything is running smoothly now and this person is worthy of being your partner, then you need to decide if this is the only reason holding you back and if it is a worthwhile reason.