Advice picking graphics card for new iMac 27 5k Retina (for music production)

[Gl00my]

Hey guys, I ordered an iMac 2020 27 inch 5k retina. I picked out an i9, 4TB SSD, 8GB RAM (will upgrade to 128GB myself) and a Radeon 5700 with 8GB GDDR6. I can still cancel my order and change it; and I was just wondering is it worth it to get the 5700XT? I can afford it but wanted to know if it is necessary or will give more longevity. I will be using Logic Pro X with lots of modern VST's like Native Instruments, Arturia, Omnisphere and plugins. Eventually I will have projects with 20+ tracks of audio that all need plugins for mixing. I'll do some occasional video editing - nothing major, just putting stuff I film on my GoPro into FinalCut to make a movie, then putting that in Logic to sync up with music. Just wondering if it might help to have 5700 XT over the 5700?

Thanks!
EDIT: I know the M1 processors are around the corner, but they've only been rumoured to come first in the 21.5 iMac in the spring; and I can't wait longer than that for a new iMac, hence me buying now.

 

[MarkC426]

Not sure of performance benefit, but being in an iMac I would get the highest spec gpu you can afford, as it‘s not upgradeable.

 

[wilberforce]

This may be helpful. It shows little difference between GPUs for Logic Pro (jump to 5:40), but a big difference for other things: