Hello there Eric,
Interesting calculators there.
One thing i found was with the LM317 calculator. It allows a power dissipation of 2 watts without a heat sink. That's OK for the TO-3 package but not OK for the TO-220 really. A better limit for the TO-220 is 1 watt. That's because the TO-3 package has a thermal resistance of about 35 deg C per watt, while the TO-220 package is about twice that, even a little more like 80 deg C per watt. A temperature rise of 80 degrees C is quite a bit for a device even though it might be able to take it because considering ambient that means the package will be at the same temperature as the boiling point of water and that's with only 1 watt, so imagine what 2 watts would do
Also, a minor point, it's a little unclear that the power dissipation being shown is for the load resistance or for the package itself.