Just want to mention that a 4070 works without any modifications in my R9 (4070 MSI Ventus 2x 12 G OC). The metal triangle doesn`t have to be removed, there is enough space left (width). Also the 8 PIN power connector fits.

link: MSI GeForce RTX™ 4070 VENTUS 2X 12G OC | Graphics Card | MSI Global

The card runs great so far. Cooler and much quieter than my 2060 Super OEM. No coil whine too.