Sure, but why the exception for the attribute extenders. I just found out that either of these work.
Code: ags
bool seti_DialogGuiOptions(static CustomDialogGui, eDialogGuiOptions index, int value) {
}
// works too on a static struct, but it should not
bool seti_DialogGuiOptions(this CustomDialogGui*, eDialogGuiOptions index, int value){
}