The flat upper surface of the sidepod could create more lift, as the air will want to separate after a while (even in a straight line - air does strange things, and doesn't like not doing anything), but it depends how the air is fed to and taken from it. Around the sides it is quite simple, with the undercut blending out sooner than on most cars, but again that is still probably 99% of the way there.
Remember - new team; just being on the grid and within a few seconds of the pace is a damn good effort. They aren't expecting to come out with something that rivals the complexity of a McLaren!