Honestly - 1" should be fine... that works out to about 28mm, and the 10W3 isn't capable of anywhere near that excursion.
In fact, some people create loading pannels for their subs to create this very effect. It actually increases the output of the subs, most often.
I'd simply leave it alone.
If you are concerned, there are other things you could do that would be MUCH less painful... such as simply recessing the sub.
That would be as simple as cutting the hole in your enclosure large enough for the sub to actually fit
through, and then making a baffle (you might need to make it in 2 pieces, sealing it well when installed) that will be screwed inside the enclosure, that the sub will actually screw to, making the sub mount flush with the outside of the current enclosure. That would buy you a full 3/4" more room, which definitely would be more than plenty.
Just curious, if you are experiencing any negative symptoms right now at all (other than know-it-all friends)?
I'm doubting it.
