When you recorded the boundary was there some buttons active on the screen like "pause" or "finish"  something like that?  I can't remember even though I just used my 500 last fall.   All you need to test is an area bigger than your implement width in the 500.  Start a new field and practice in the yard.  I did that like 4 times when I got my 500. 

I loved having boundaries, but mostly used the headland pattern.  Mainly because when spraying you knew just how much to put in to finish.  Then later for guidance on the headland.