Nice writeup! I've spent the last couple days deep in the mathematics of voting power, and I will hopefully have some solid analysis to add to your strategy. In particular I'm going to ask "what average voting power maximises the value of your votes?" Vote too much, dilute yourself; vote too little, miss out on opportunities to vote. I don't know offhand what the number will be, but I wouldn't be surprised if your 75% is not far off. Keep an eye out for my coming post!