Always use the highest potential voltage for calculating amp draw... NOT the reduced voltages that result from drawing amps or parasitic loss due to materials and construction.
One, I explicitly said it's not good practice to rely on voltage sag to keep you safe. Safety overheads are important.
Two, Those amp ratings are based on the actual current coming out of the battery, not some theoretical calculated amperage.
Three, I always do the calculations based on emf and accounting for internal resistance of the cell because if you're not adjusting for it then things can work out poorly.
If you are always calculating based on
just the emf and coil resistance alone, you are going to over inflate the calculated wattage, so if you properly calculated the heat flux per watt for your coil build and adjusted it to be high but not scorching at full battery...
Then congratulations you now have a build that is going to start at the low end of acceptable and quickly become anemic.
I always recommend new mech users know their equipment and how it works, stay under CDR and ignore Mooch's MVA rating to start, calculate their minimum safe resistance using charged battery emf, find their wattage separately from minimum safe resistance accounting for battery internal resistance, check their resistance with the top cap off, and again with it on, and if anything is unusual or doesn't make sense, to put the whole thing aside and use something with safeties until they've figured out what's going on.
BUT when you spread misinformation you do the community, new users, and yourself a disservice. You are putting new users in a situation where following your advice will give an unsatisfactory experience, and it's easy for them to ascertain that you misled them making them question all advice, particularly safety advice and anything else they've heard from you. Then, when they do something unsafe because they are disregarding safety information, the backlash and image problems are felt by the whole community.
When you reduce the complexities down to that's "how to make a mod go boom" it's easy to tell you're wrong. Aside from the fact that an Alien will happily fire 220W on 20A cells drawing 30 to 40 amps without blowing up, every mech cloud bro that, based on the way you say to calculate things and the consequences, shouldn't have their front teeth is a counter point.
Most of the venting and explosion events come down to loose batteries outside of a device, pocket carry of mechanical mods without a lock, or hybrid top caps with atomizer with non-protruding positive pins.
Generic battery safety information will go much further in preventing accidents.
Teaching people how to
effectively build for a higher resistance so the vapor production and flavor are good without bleeding edge amperage will go further towards getting people to make safe builds.