I firmly believe that you can practice them very appropriately without having to go down below 500ft.
You can practice the last bit every time you make a glide-approach into the airfield you fly from/to.
The most important bit is the bit above 500ft, as in setting it up, field selection etc. If you don't get those bits right you can forget it. Nobody saves a botched set up with that little height/time left.
FD