This looks pretty simple actually. It looks like the hardest part will just be taking the phone apart to get access to the back of the mainboard and then putting it back together. You didn't even have to remove any shielding! Pretty much the only part that isn't reversible is melting the adhesive to get the back cover off right?
What's the model of the charging pad that you used? I'd like to try this myself.
edit: looked at some charging pads on Amazon and it looked like the pads made for the S3 are 500mA while pads for the S5 are 1000mA. it looks like you were using the S5 pads. Have you tested what the maximum current from the charging pads are?