Kachok, I' much like you, in that, I'm always pushing the limits and have also found some of my most accurate loads are those that contradict maximum published data. And I do it in the 06, .243, 6mm /rem, .270, and some belted mags too. this is one of the advantages to reloading, is we can make those decisions, and at our own risk of course.
Whether or not I've taken a cartridge up beyond SAAMI spec, who knows? But I would venture to guess I probably do and on a regular basis, and I manage to still get some pretty good life spans from my brass too. Right head space, precision assembled cartridges, a strong action, and a safe work up procedure will get up there safely. Just closely inspect each piece of brass as you extract it, only make SMALL increases in powder charges, and you'll be able to intercept any serious problems.
I will say this though, if you load with this mind set, you must be well versed in what to watch for in every aspect. I would be lying if I said I never had a head separation, but I was expecting to see it on those few occasions I've experienced one. Since I was using brass that was approaching it's last run, and incipient separations are a part of my world, since I run my brass to the absolute limit.
Keep a close eye on things, and don't introduce large charge increases to the process.
GS