Quick Qestion
 

Looking at the default mainhud.effects.xml, it appears that max number of displayable effects is hardcoded at 30, yet in the game often due to proc effects I can well exceed the 30 slots, are the effects being over written, or just not displaying due to the hard coding?

Just not displaying (you can easily check that on raid when you see all the -debuff x number of same class- on your favorite named :D ) .

Yes, it is hard coded. No, a UI mod can't change that.

disconcerting
 

To watch hate transfer buffs low down on the list vanish when armor, or other temporary effect fires off... :(

Target window with debuff counter like group window?

Yes, it has the same restriction (30 buff view only) and when you target your raid named at pull you will see ton of debuff/dot filling until the limit (viewable) even if you add your later.