Some people will just use 4.2v in ohms law then push it by adding a few extra amps above cdr when they could have used 3.7v and stayed within the cdr.
But then you lose part of the idea of keeping a big enough safety margin to also account for unknown factors. My own personal approach is to turn unknown factors into known factors and still end up having enough safety margin for me to be capable to disarm my mech mod in a safe fashion and without panic in the rare event that the mod starts to auto-fire on me unexpectedly, and to always avoid any and all accidental button presses the same way you can always avoid driving yourself off a cliff. On a "faux hybrid" (i.e. direct-to-battery) mech, the battery can get pressed against the inside of the top of the mod if, before you unscrew the button, you unscrew the atomizer... thereby potentially causing a hard short followed by a battery explosion. But this can always be avoided by simply always remembering to unscrew the button instead. But if the mod starts to auto-fire and then you panic as a result from that, you might not remember this. So either you have to be sure that you won't panic or else you can get a mech that uses a 510 pin such as the Broadside. Only if you're the type of person who easily starts to panic or who has trouble remembering important stuff, like, for example, trouble remembering that you should never ever screw on an atomizer that doesn't have a protruding center pin excepting only if your mech mod isn't a faux hybrid, you should probably stay away from mechs in general. I mean, going above the CDR makes the battery heat up faster so you'll have less time to react in case something goes wrong with the mod. But not everyone knows how to react correctly, and not everyone knows how to always stay alert and to always notice it on time so therein lies part of the culprit.
Another surefire way to make accidents happen by going above the CDR are people who don't understand when it's time to put the mod down and give it a rest. The higher you go above the CDR, the faster the battery heats up. But for reasons that are obvious, immediately as soon as you let go of the fire button, the battery cools back down again. If you're not familiar with the relationship between how fast a given battery heats up and how many amps you draw from this same battery for how many seconds, just pull out the battery each time when in doubt. Feel how warm it gets. As long as you don't immediately build to ridiculously low ohms, as long as your coil build is stable and your ohms reader is sufficiently accurate, if you can understand everything I have been explaining so far, you can familiarize yourself with all these factors. Using a .11 ohms build on a single Sony VTC5A is way above the CDR of 25A for this battery. Does that make it so unsafe that you'd have to be a jackass? Hell no, it doesn't. Even after you take like 5 hits in a row each one of which lasts almost 2 seconds, the Sony VTC5A in a single battery mech at .11 ohms gets barely even lukewarm. Above 45 degrees Celsius is where a battery starts aging faster than normal. 35A is not the CDR of the Sony VTC5A. Instead, it is only 25A. Despite this, the VTC5A is rated by Sony to 35A Maximum Continuous Discharge Current
IF you make absolutely perfectly sure that it stays below 80 degrees Celsius. You do get an increased risk of the battery venting if you go above the CDR. You really do, but my question is, does it take to be a rocket scientist to make the battery always stay below 45 degrees Celsius so that you still have time to react appropriately before it can ever get to 80 degrees Celsius? You be the judge. Finally, because the Samsung 20S has a CDR of 30A and because it is hitting so much harder than the VTC5A... well, you get the picture.