I was up all night worried (not really) about the AFC drip tip not fitting in some of the Zenesis and it got me thinking.
If it's only off by a very small amount you could freeze the driptip

and if need be heat the cap

and through the magic of contraction and expansion you may get them to meet somewhere in the middle.
There is one caveat, you should really make sure you love that drip tip, because reversing this process and getting the drip-tip out may be an excercise in futility. Not to worry Zen sells replacement caps if you lose them....or permenantly press-fit them to a drip tip.

You may be removing the entire cap to dump condensation out as you may not get that drip tip out of there without a herculian effort or an act of God. I guess you could oil the hole first & even this may not help you retrieve it after it expands, but maybe it will give you fighting chance.
A few years ago my company had a problem on a media server product we manufactured where a thick curved piece of T6061 aluminum machined with the product name and company logo that required a different finish than the rest of the front panel of the chassis. It was intended to be machined for a 'press fit' to a female inset on the front panel of the product's chassis, but unfortunatley it was machined slightly too big to be press fitted as intended. We froze the piece and quickly popped them in and once it begin to warm up and expand they were like one piece which was intended as it made the front panel look like it one piece of metal and not the kludge it actually was.
So you must ask yourself; "are you crazy enough to try this?"
The hard part of this post was deciding between press fit, pressed fitted, pressed fit, or press fitted. I still don't know which is correct!