I do think that mentally it does make a difference. I just got a Sterlingworth restocked and have shot 4 rounds of skeet. It is choked 13&30. I am very aware of this and I believe that it is detrimental. More mentally than actual but detrimental just the same. In my mind I want to be careful especially with the full choke. It reminds me of when I first started to shoot a .410 at skeet. I had a hard time not treating it like any other gun, as you should. When I have intense focus on the the bird I shoot it well.
Am I going to shoot a full choke in skeet competition....hell no! But I am going to start shooting a little tighter choke at the larger sporting events that have more difficult presentations.