Redmine

I sometimes want to create very small but very helpful plugins that will contain a few javascript+html lines to help the UI in some screens.
Examples:
Tracker/edit : hierarchy mode button (tick/untick subprojects of ticked project)
_attributes : add javascript to insert a "disabled" attribute on an attribute

I don't want to override the view because I think the methodology of overriding views when you need to manage multiple plugins will lead to maintenance problems.

Why there are no hooks on some of the views?

Thanks.