I did the 160mm size for the drawers which were over 30" and the 128mm size for everything else except for my narrow pullouts. I used the 3" pulls for those. I liked the 96mm on my narrow drawers (15"), but DH preferred the 128, so that's what I did. I think if you stick with the 128 everywhere except for the one big drawer you won't even notice that it is a different size pull.

It works! I saw this thread last week, and decided to plan in some of those hidden drawers into our kitchen plan. DH liked the idea but needed a bit of convincing evidence, so this morning we went to Ikea. We brought some masking tape and a couple of flat magnets and asked one of the kitchen staffers for an ok. We tried your "fix" in one of the showrooms, using the masking tape to secure the magnets. After changing out one of the magnets for a stronger one and after a try or two, YES: we were able to predict which drawer would be visible when opened. It really did feel like magic. The kitchen staff and other customers were impressed too and everybody wanted to give it a try as well. Lots of laughter and oohing and aahing. We had quite the little magic show at Ikea today! :-) Thanks Pippa for sharing this.

There is also a consideration of leverage and reach. It's easier to reach higher to the hardware on the lower drawers, and it's also easier to pull a large drawer open front the top rather than the center. Many other template examples would show placing pulls on the top rail of the frame of the door for these reasons if possible. Here is an example of such placement on cabinetry from the luxury company William Ohs.

A 3 inch center to center pull will not look weird. ...........as long as it is SLIM enough to sit in the space. Forget about a cup pull is the point. Note too, that a five inch pull looks great on doors as well. So too can a three inch. Show the actual pull you are considering..................and know that ONE centered pull on large drawers is actually easier, and means ONE hand to pull out and more stability over time on the drawer use.. Longer than 5 inch on those large drawers.......like nine inch.:) So consider the ENTIRE CABINET plan.