.can't visualize this! you mean a stop at the foil?If you use a sail with a short luff remember that you will need a strop at it's head to let the luff slider get up to it's right place on the foil
If the luff slider doesn't get high enough up the foil, you will get halyard wrap when you try and furl. So a sail with a short luff (working jib, say) will need a length of line (or a strop) between it's head and the luff slider to prevent this happening.