I was bored and decided to crunch numbers on a spreadsheet, and noticed that while most of the power flowers get a progressively better return on investment(starting out at below .005%) the Final power flower breaks that trend.

The Fading power flower returns about 0.2% of its EMC value per second.
The Final power flower returns about 0.06% of its EMC value per second.

Given the values involved I'm not sure if this should be altered or not.

definitely doesn't need to be altered. You make that last one to finish the progression, and you're basically creating an infinite source of EMC. No person should ever be able to use that much emc every second no matter the size of the factory or anything of the sort