Got a few when Polaris first rolled out, no need to use the Lavs at all for changing, on TPACs I wear them underneath zip-up hoodie and jeans then just slip out of the jeans underneath the big comforter/blanket after the first meal and the lights dim, and put them back on shortly before the arrival meal. I also always pick the window odd-numbered seat on 77Ws for max privacy. *Caveat - don't do this on the Dreamliners or the IPTE seats lol