So I guess I am just out of Luck.

For cell phone manufacturers it's apparently relatively easy for them to design the screen for any given phone, and as a result it's actually fairly rare for a screen to fit more than one phone model, so it really shouldn't be a surprise if the Edge 20 Fusion screen doesn't fit the Edge 30 Fusion.

DISPLAY Type OLED, 1B colors, 90Hz, HDR10+

Size 6.7 inches, 108.4 cm2 (~85.9% screen-to-body ratio)

Resolution 1080 x 2400 pixels, 20:9 ratio (~393 ppi density)

DISPLAY Type P-OLED, 1B colors, 144Hz, HDR10+, 1100 nits (peak)

Size 6.55 inches, 103.6 cm2 (~90.8% screen-to-body ratio)

Resolution 1080 x 2400 pixels, 20:9 ratio (~402 ppi density)

Protection Corning Gorilla Glass 5

Given that the dimensions are not exactly the same and it appears there's some difference in the technology (OLED vs. P-OLED), my guess is they're not going to be interchangeable.

Is there some reason you really seem to want to put an Edge 20 screen on an Edge 30?