Here are some specs that might help. My 'glass boat has a skeg measuring 3 x 13 inches, 20 square inches. In serious wind with four foot wind waves, many of them breaking over me I have found that with the skeg up I get serious weathercocking, almost too much to correct with the usual edging,etc. Forward progress becomes pitifully slow and exhausting.

With the skeg fully deployed I get leecocking, but not so much that I cannot correct with the usual edging, but I am a little too busy in these conditions to want to spend time and energy this way.

The answer to this is to drop the skeg halfway, ten square inches, and it tracks like a train. I have been two miles from home in the above conditions and set the skeg halfway and even with a following sea when the boat is wallowing this way and that and the bow thinks it is the front end of a submarine it heads straight home. This blew me away the first time it happened.

So it would be good to get out in the most serious wind you are willing to paddle in and modify your skeg accordingly.

If you should need to remove material you may want to leave the length and height alone and remove material from the rear forming an angle that will allow you to slide over things you may be backing into. As it stands the perpendicular rear of the skeg could catch on whatever, and there is a lot of whatever out there on the water.

Bob