Thanks Allen.

Do you think having the lazy jacks threaded through the grommets in the
cover makes the system work better ? I guess there is enough friction that
the covers stay up when desired, yet can be slid down for sailing. Did I get
that right ? Probably reduces chafe on the cover as well.

My lazy jack "halyards", I suppose they could be called, after exiting
above the spreaders, pass through fairleads inserted in holes in the
spreaders to do just as you were told.