To get rid of the GOP error, i'm afraid you most likely have to flash your RX 580 BIOS/firmware to another version where the GOP is implemented properly.
Here is a collection of RX 580 firmwares:
https://www.techpowerup.com/vgabios...el=RX+580&interface=&memType=&memSize=&since=
You can find several people who had GOP errors on RX 500-series cards, which only went away after flashing the card's firmware.
But beware, if you flash a firmware that's not suitable, you could brick the card. So read up on it carefully.
With the motherboard's BIOS set to UEFI mode, it always requires the graphics card to have a GOP (Graphics Output Protocol driver). It seems that on some RX 500-series cards they have messed this up somehow, i have seen some examples like here,
https://forum-en.msi.com/index.php?threads/graphics-output-protocol.369201/#post-2091095
Not using UEFI mode would create another problem: Windows 11 doesn't want the BIOS in CSM/Legacy mode, it wants it in UEFI mode.
However, your original question, about the RAID0, that should be the least of your worries. RAID0 will improve the speed in benchmarks, the linear thruput will be higher of course, but in reality there is not much left of that. The renowned German "c't magazine"
tested an NVMe RAID0 with four SSDs on a Threadripper workstation, and while the measured thruput increased massively to 14.6 GB/s, in real-life applications it wasn't any faster than a single fast Samsung 980 Pro. The article is in German and behind a paywall, but i have the magazine and i've read it in full. It has to do with access times and where the bottlenecks really are as to why it can't be much faster in real-life tasks.
Add to that the fact that RAID just has a tendency to create all sorts of problems along the way with the BIOS setup and so on, i read it regularly on this forum. So nowadays, especially with SSDs, a RAID delivers no tangible benefit, but can result in some clear disadvantages. That's why i do not recommend using it anymore.