https://www.bmwblog.com/2019/06/10/a-closer-look-at-the-future-bmw-m3-m4-engine-the-s58/
The entry-level version of the S58 delivers 480 PS (473 hp in the US) and offers 600 Newton meters (442 lb-ft) of torque, making it more powerful that even the engine found in the M3 CS and M4 CS models...
Even though the 2020 Supra might have better incentives I would suggest waiting for the 2021. Toyota has improved the platform enough that it warrants holding off on the previous model.
That software flash would be a better investment for the A61 in my opinion.