Is this leg still on?
IE why not Pwll to Holyhead?
A trip through the Straits should not be missed for many reasons but it's kind of a divertion and Conwy can be a bit of a nuisance to get in and out of sometimes.
Don't get Me wrong, love to see You in the Straits area but a call into Caernarfon or Port Dinorwic ( for vitals and fuel) at the Southern end and then on to the IOM seems more practical.
I can organise fuel etc at the above by the way.
Plus a trip through the Swellies, or Pilotage through if Conwy is a definate destination.
Cheers
R
K