Will the loom stretch the piece when I wind for a long piece?

I have a Cousins DIY loom. I am beading a 24" long piece using 11/0 Miyuki Delica beads. It seems like when I cinch the weft threads the piece will be narrower than the width where the threads meet the dent coil and will stretch the piece when I need to wind the piece in order to complete the piece length. Is this a valid concern?