If I add a GPU later, will I need to go through the entire installation process again?

Hi, I have a desktop with i9-9900K and Z390 motherboard. I read that the 2080Ti will be ignored by Mac OS. I am considering to try out the iGPU in the CPU first and if the performance is not satisfied, add an AMD GPU. If I need to add a GPU later, will it be just plug and play (i.e. Mac OS automatically recognizes the GPU and install/use the appropriate driver) or I have to install the GPU into the machine and then go through the entire software installation procedure again?