I recently got the La Spalla Navy Jacket, which I actually love. But recently, I've noticed that the sleeves on the 36 regular are a little bit short for me. So I was going to let them out a little bit at the cuff, around 1/4", but I've read that the appropriate distance from the end of the cuff to the center of the first button is supposed to be around 1 to 1.25". What's strange is that the La Spalla Jacket I purchased has a distance of 1.75" off the rack, so adding another 1/4" is going to make it 2". If the norm is to have the distance be between 1 to 1.25", why does the La Spalla have 1.75" off the rack? Does it look strange already and will it look worse if I let the sleeves out? The pics are how it is off the rack.
If you're that concerned you could have your tailor add another button. You should have an extra button inside jacket and also interior waistband button can be swapped out with any button, as no one sees it. I've had a jacket's sleeves extended by 1/4" - 1/2" and never thought about it again. Someone might notice someday. Would I be mortified if they did? No.
I would be more concerned wearing a sport coat with flap pockets. That wouldn't work for me.