I specifically said swords, but Finally someone pointed this out, thank you.
Off handing a weapon with 999 delay will get you 25 tp a round. It was an intentionally stupid example, but I guess nobody got that I was kidding.
Anyway, thread is basically over. OA3 is marginally better, OA4 will be that much better. Before, I said it wouldn't be worth the time investment for a marginal upgrade, but assuming TotM continues to add upgrades at 95 and 99, weather it keeps increasing the OAX or the base damage, it's worthwhile in the long run, if offhanding a multi hit is what you're after, go for it.