First off, welcome to Sailnet, Trace
Secondly, since travel-lifts should only be operated by experienced marina staff, I'd have thought there'd be a marina supervisor with sufficient experience to know exactly where to place the straps.. since any damage to the boat caused by the straps being in the wrong place is on their insurance - not yours.
Nevertheless, it should be relatively easy to locate the forward end of the rudder and pull the strap up close by and then it should be pretty obvious to all if the rear strap isn't sitting snugly against the hull (ie. fouled on the prop) before
taking any weight.
Once the boat is out of the water, have them mark the hull for next time.