I think you just answer your own question. I am not here to tell you how to bet, or what to bet.
If your records show that you would have made a profit by backing only teams who are at home, then this is the way to go.
However, dont just think that you can play more home teams, at the moment you must be doing something right. So cap your complete card as usual and play only the home plays and use the money you would have used on your away teams and put it onto your selected home teams. Therefore you are increasing your profit/returns.
Remember, the more games you play the more chance of losing.
PLAY WISELY AND YOU HAVE EVERY POSSIBILITY OF WINNING