Mm, whether it feels contrived or not matters. In my opinion, enjoyable fanservice happens when it's clearly a part of the scene no matter how you look at it (Protagonist accidentally walks in on Love Interest in the shower, hilarity ensues), and irritating fanservice happens when it's tacked onto a scene where it's not immediately apparent that it should be there (Fully-clothed Love Interest is talking to Protagonist on the phone while laying on the sofa; camera cuts to an upskirt).