I tried it a few times and found it to be more of a hinderance than a help. At least for me, I get a better picture of what's going on around me with the F9 view.
I would also think that padlock view would actually hinder your SA and not give you a complete picture of what's going on around you. The reason is because you become dependent on the padlock view to keep the bogie in site and you become focused on that one target and lose the awareness of what's going on around you. Sure, you might be able to track your target better since you're so focused on him but what about the bandit that is closing at your high 5 O'clock, or the other bogie at your low 8 O'clock climbing up to you getting ready to take the lead angle shot? You'd have a better chance in spotting these bogies as well as get a better idea of what's going on around you outside of your cockpit with the normal snap or instant view keys.
Ack-Ack