Currently, most of the MathML attributes are parsed in the renderer classes, while we should follow the standard way and parse attributes in the element classes. Hopefully, this will improve the management of dynamic update. There is already bug 118900 to do that for length attributes but this is a meta bug to track the most general case.
*** Bug 118900 has been marked as a duplicate of this bug. ***
All MathML attributes are now parsed in element classes.