I just read that page. I'm glad it was several years old, although I couldn't find an actual date in the source code. That info may have been correct years ago, but now it is down right dangerous. Today, with the high drain 20 to 30A batteries we use (and the brands we recommend due to reliability and safety) heating issues on premade atomizer coils isn't really an issue. Unless you are using low quality cells.
For example, on a recommended 20A battery, I know you can build as low as 0.21 ohms and be in the "safe" discharge zone. Which is a 20A draw on a 20A battery. No build is 100% safe of course, but you reduce risks as much as possible. Now as you can see, 0.22 ohm is much lower than 3.0 ohms. Most regulated mods today will not even go higher than 3.0 ohms (or lower that 0.10 ohm) as defined by the IC board in the regulated mod. (not to be confused with hybrid and non-hybrid mechanical mods, which are advanced user mods)
The guy is correct in one thing. It is about what YOU like. For flavor on factory coils, I have found 0.50 to be very good. (for a factory coil that is) and 0.30 even better. Heat you adjust with wattage and airflow. Mostly, we just say start low, work up. Low power, low air, adjust up until you hit your sweet spot.
One more factor, is that the coil build is more important than the ohms. Using factory coils as an example, clapton coils give better flavor than a straight single wire coil, because they trap more juice. Straight coils produce more cloud, because they burn juice faster.
There is more, but I'll leave off here. This is the basics.
*** The CDR (constant discharge rate) is the number of amps, tested at the factory, that a battery can be discharged at, without heating the cell and without damaging the battery *** We only recommend Samsung, Sony, LG as the factory do valid tests and give accurate results.
With todays regulated vaping mods, the IC board regulates amps, voltage, etc so it isn't as much a factor. As I said, most regulated mods will accept coils as low as 0.10 ohm safely, as the IC board "regulates" the amps and wattage calculations and adjusts accordingly.
I just wanted to add a bit on battery safety as the guy who wrote that page mentioned it. Regardless of what kind of mod you use, new user mods or advanced or expert mods, battery safety is the number 1 factor considered. This prevents incidents like you see in the news casts about vaping mods blowing up from happening. As much as some people want to blame vaping, the simple fact is, a blown up battery is 100% the result of user error.