Domino Server Version vs. iNotes template version

I need to upgrade our server to 6.0.3; currently we are at 6.0.2 cf1. We have added customization to the current iNotes6 mail template that is only available via the Notes client. Life will be much easier if I do not have to add this customization to 6.0.3 iNotes template. Am I going to have problems the 6.0.2 cf1 iNotes5 template on a 6.0.3 server.

Thanks

David