In looking to upgrade my 10yo grandson from a single barrel 20g shotgun to an O/U 20g gun ready for next years gamebird season I have had a look at a KOFS O/U in a gunshop. They make a youth version in 20g with a shorter pull and 26" barrels. Well made and finished with very nicely figured Turkish walnut wood. Despite the shorter stock the gun came to my shoulder and pointed extremely well and the action opened and closed smoothly, not like some cheaper guns which are often too tight and clunky.
My grandson recently used the same gun shooting clay targets at an event our family held for one of our son's 30th birthday. He did well with the gun and loved it.

I wouldn't hesitate to have one of the KOFS guns in 12, 16 or 20 gauge. I imagine the manufacturer of the KOFS guns just standardise their chambering to 3" for all gauges, the 16g being the odd one out in so far as 3" cartridges are not currently (or commonly?) available for that gauge.