please help with adjusting my training plans

Background:-
I have just finished wk14 of 16 of Run focused OLY from BT, leading up to my first OLY in2 weeks time. Apart from swimming (which I am confident at) I have pretty much stuck to the plan which had highest training hours of about 9hrs.
Extra info that may help is that I did go out once and run for an hour and a half a few weeks ago whereas the longest run on the plan is an hour and a quarter. Also I have done about 3 x 2.5 hour rides (max 41 miles).

Now, because I have plans to do IM next year it has been suggested that I do a HIM aquabike which is local to here and 2 weeks after OLY. BUT, I have looked at the beginners HIM plan and I noted the following:

1. swim - I am ok with distance with as I swim with masters weekly 3250m (about 80mins)
2. Bike - there is only one ride longer than what I have done to date - a 3hour one scheduled for next week if I swapped plans
3. Run there is only one run which is longer than I have done to date - a 2hour scheduled for next week if I swapped plans. However, there have been a few 1 and a half hour runs and although I regularly run over an hour, I have only done one of those).

Also the aquabike is the same price as HIM, have to be there day before etc etc and I think "well why not try it then". I don't want to injure myself. But, I would just be looking to finish for the experience.

So, I guess my first question would be "am I being sensible considering this?"
Assuming I am (I get rather enthusiastic about my abilities!) then I don't think a long bike and long run as said above would be very sensible in the week prior to my OLY. So what does anyone suggest to plan for this? Shall I do a 90m run and 3hr bike this week and taper a bit next week for the OLY then pick up the 2 week taper for the HIM after the OLY

This was so easy when I was unfit and just had the one goal in mind of "finishing an OLY"

Sorry for the essay but what does anyone think/ suggest.
thanks
Jackie