IM 70.3 Advice

Congrats on your achievement!

If you liked the plan, and your goals are pretty much in line with it, then why not just start the plan again ?
Seems like there is enough time to follow it in entirety..

Even though there is the initial build phase, and it might seem too easy, this will allow you to take a breather from training until the plan gets harder.

That's just a thought. If it's too boring I would add perhaps more swimming and bike miles, but be careful not to over do it on the running.

My 2 cents...

You could follow the plan once again and like said add in some more swim biking time and maybe some extra limited running time. You might even be able to cut back some of those longer 2 hour runs to 1:45 if you are covering say 16 miles vs 13 miles in the 13 hours.

5:30 isn't a bad HIM time by any means. I bet by following the plan again you will be able to cut off another 15 minutes if you do the same race with same conditions.

Next year when I do another HIM, I plan on following the plan I used before and even though I know that I can complete all the workouts I know I can make them just as hard as they were the first time but my speed will be faster overall.

The BT plans have different levels. If you used the beginner plan last time and you were able to execute it without injury or excess fatigue, you might want to move up to the intermediate level. It requires a better base than the beginner plan, which you have. Congrats and welcome to the addiction!!

Thank you for taking the time to get back to me!... Some great ideas to take into consideration.
All the best