This is an interesting thing I've discovered: I have a 45W Samsung 2.0 (third-party, so take with a grain of salt) plug and the charger that came with my phone. I have another that came with my galaxy book 4 edge and a third-party one. Interestingly, I got different, repeating results for each cable. All show the exact same charge time and Fast Charge 2.0—images provided.
Perfectly happy with the amazing charge time, so this isn't the topic. I'm more intrigued by the results showing the same charge speed regardless of the wattage.