i feel the opposite; I'd never wear it alone outside, but i don't think there's any sweater i'd wear alone on a day that was actually cold. however, I started wearing mine inside regularly starting in October and obviously still am.
i like my uniqlo socks but they seem to get a little swampy if put to the test with, say, walking on a hot day. i've been blaming the cotton-poly blend but who knows. i'll still buy more as my various pantharellas wear out.
I imagine there's gonna be a lot of pinching at the material to make sure you're only sewing through one layer, and otherwise, you should probably use a curved needle so you can get in and back out of the jacket without needing a Portal gun