Typically I want to age 22oz bottles, but I'm curious if I could get away with aging a smaller bottle. Is there any difference based on bottle size?
In theory, larger bottles mean that the little bit of air trapped at the top of the bottle is smaller compared to the volume of beer than it would be in a standard 12 oz bottle. However, I've been unable to find any research backing this up, and anecdotally it makes no difference.
Larger bottles are favored for aging beers mostly for practical reasons:
But taste and aging-wise, there's no benefit to larger bottles.
This is an incomplete answer, but I know that there are some smaller bottles of "old ale" beers which are made for aging. In particular, there are several from the UK which are sold in the 200-300mL range, such as Thomas Hardy's.
I'm afraid that I can't tell you anything about the effect (or non-effect) of bottle size.