Understand that, but my worry is that at Security they have no idea of the distinction, and just say "100 is the limit, yours says 200, no go".
You run that risk. Some of the security people may have educated themselves. Others, not so much. If you get the wrong sort, you lose your power bank.
I also see various voltages cited above: 5V, 10V, 3,7V. Unless it's something that actually shows up on the nameplate, don't try calculating what the internals of the bank are. Odds are you'll just lose 99% of the security people in confusion and definitely lose the bank. It's 20,000mAh, 5V at the terminals. That's 100Wh, right on the line. What actually goes on inside the pack (buck-boost converters, etc.) is way above their heads.
And I'd suggest not making up your own sticker, because if they spot it (and the probably see a lot of these banks and know what looks odd), you may miss your flight as well. Buy the 100Wh, 100W power bank.