In addtion to that, you also need to count the TP from jump and high jump. For every overflow, there is going to be a jump or high jump DA and make up for the wasted DA, not to mention you now have sekkanoki every 5 mins, a bit of TP overflow is not as bad of a problem as before. In addition to that, unless you are fighting EM mob all the time, you are not going to have capped fstr for either TPing or WSing. In other words, you are not going to be able to take advantage of the higher fstr cap on anything meaningful like you have suggested in your calculation. All that will be big factors to consider. Also not to forget, the more frequent you WS, the more frequent your wyvern will be doing breath attack, and those breath attack won't go down just cuz you are using a lower dmg weapon, they stay the same. So the more you spam the better it is, unless of course you don't count your wyvern's damage or won't be able to keep it alive then that's a whole other story.
Stp gears from the new update will make true 6 hit much easier with 492 delay polearm (now that with sonic thrust, a true 6 hit becomes slightly more important especially for harder mobs), tho OAT polearm will be able to use sword strap if that extra delay is not needed. Also, who is to say that Rhongomiant will be the only final skin for magian weapons. I suspect the next two updates, we will possibly be getting the final skin for the OAT line and others. Remember, there are 3 addons, it wouldn't surprise me to see two more final skins. Not to mention, getting Rhongomiant is no cake walk, it is far harder than OAT comparing their last trial.