I "discovered" the advent of the SP 45ACP a while back when the primer could not be seated in my Classic Turret Press.
Upon inspection, I had a fair number of them. I set about separating them from the LP casings. This was a one-time process. After cleaning the casings that I've shot/picked up I always tap them on a hard surface to remove any media that might still be inside the casings. At that time I separate the 2 primer hole sizes. As I'm still getting the brass for free I got over it quickly. I have around 3000 LP casings and maybe 300SP casings. So, I don't really need the SP's but I'll hang on to them and use them if I run out of LP primers or the price differential in the 2 primer sizes becomes profitable for me to do so.