I've done and not noticed any particular problem. Note that wide open, your results with close focus may vary, depending on a variety of factors. To wit, CL does not have the longest rangefinder base length for accuracy; opinions differ on lens register for which FSU lenses were designed; and individual copies of the lens can vary (esp if 'maintained' or 'fixed' poorly).
But at moderate apertures and decent distances, I've had completely acceptable results (I haven't rigorously tested at close focus). If you use the right adapter, the right framelines should be on. It makes a nice compact and good-looking combo, especially with a nice hood. Of course, the 40mm lens designed for the CL is even smaller.