Northwest, around here back when I flew a lot of sailplane competitions more than one person had sandpaper grip pads on the fuselage to make holding it easier against the tension. This applied to both highstart and winch use since the really serious guys stomp on the winch and wind it up until there's easily the same or more tension than you're feeling with the high start. Only at that point do they give 'er a big javelin like throw to get the model off to a really good start. A slip at that point could be.... shall we say.... "interesting"?
So the sandpaper patches are really something to consider if you find it in the slightest way uncomfortable to hold the model.