Sternone's picture shows the 172RG with the standard prop' in its normal stationary position. The prop' is indexed on the shaft to stop in the horizontal 9 o'clock, 3 o'clock position at shut down.
At slow speeds, and with normal compression, the prop' will stop as shown in the picture and not be subject to damage. Did Cessna know something when they designed the machine??
Propellers aren't "indexed" to stop in any position. They tend to stop on a compression stroke as the engine winds down, though not always. Cessna didn't design the engine, nor propeller, and never indended, nor designed the installation to stop in any particular position. At slow speeds, the propeller will normally continue to windmill. Shutting the engine down on final is very unlikely to stop the propeller. In this case, if you're intending to execute gear up landing and want the propeller stopped, you're going to need to do it at altitude over the airfield, then commit to a power off approach and landing. And yes...your glide will be different with the propeller stopped.
Your ability to adjust your glide path with power will have been sacrificed, of course, and you can't execute a go-around or balked landing. For those who'd prefer to stop the propeller...how many one-shot landings have you done from an engine-stopped approach with the propeller stationary? Do you want this landing emergency landing to be your first?