Well I suppose the movement can be used for other purposes but in my mind (and as far as I was taught) crossovers serve as the best exercise to hit your pecs from the peak contracted position.
I still train according to POF principles, if you couldn't tell.
All I'm saying is to give a quick squeeze when your pec hits its contracted state. It makes a world of difference in terms of muscle fiber recruitment.
Also doing it one arm I've tried that years past and it really limits the amount of weight you can use due to balance issues. It's awkward, at least for me. Whatever burn you maybe experience definitely does not offset the fiber recruitment you are missing out on due to the lesser weight you are using.
Just my humble opinion, I look nowhere near as good as you do so take my opinion for whatever it may be worth (which may be nothing.)