[NTG-pdftex] character attribute

Hi, currently a character node in tex has the only attribute, ie the associated font. I m wondering whether it makes sense to replace this attribute (font) by a pointer to some data structure representing a set of attributes. This way we can add further attributes of a character without messing up around the sources. Such attributes can be: font, color, location in tex sources, next bytes of a utf8 sequence etc. How to you guys see it? Thanh