The most import thing is .....
that no matter where you put it either at the top or bottom just be sure that the top swivel on the foil is nearly *all the way to the very top of the foil*. This will prevent the top swivel from 'binding' and having the halyrad override and possibly wrap the top swivel. Look at your furler manual for top-swivel-to-halyard *lead angle*'.
For best sail efficiency put the pendant at the top as a jib thats closer to or just touching on the deck is VASTLY more aerodynamically efficient. If you want visability then put it on the bottom.
If you want to see AND have the jib as a 'deck sweeper' ... have a sailmaker install a clear vinyl window in the genoa.