HIM training plan advice? r/o

After doing IMWI last year on woefully low mileage, my goal this year is to back up and do things right this time.  So I'm targeting a HIM in August where I really want to improve on my time of 6:27 from last year.

Right now I'm following the BT 8 week Run Focus winter maintenance plan.  When that runs out, I'll have exactly 14 weeks before starting the 16 week Intermediate HIM plan.  I plan to run 2 half marathons during that 'in between' time, which is why I'm doing the Run focus plan.

My question is what to do in that 14 weeks in between the winter maintenance and the HIM plan?  For reference, I just started it, but the plan I'm on feels quite easy.   I'm hoping to really push myself in training this year and make a big time improvement.

I'm super embarassed to type this, but last year for my 6:27 HIM, my weekly averages leading into it were about 2000 yds swimming/60 miles biking/10 miles running - almost all just 'easy'.  (And they didn't really increase leading into the IM either - yikes!)

Yes, that's all.  So you can hopefully understand why I think I can make a lot of improvement just by increasing & improving my training!

ps - if you check my log you'll notice a shoulder injury.  It's not from swimming at all, rather picking up my daugther awkardly out of the car.  Took 2 months off & finally starting back up slowly.  Other than that, been very durable and lucky on the injury front.

Thanks!