If your planning a build log for a system to run 4-GPU SLI,.. Z590 platform is not an option I would consider.
Intel Z590 Chipset only supports 24 PCI Express Lanes.
https://www.intel.com/content/www/us/en/products/sku/196612/intel-z590-chipset/specifications.htmlPersonally the best option would be WRX80 platform with Threadripper Pro processor.
https://www.amd.com/en/chipsets/wrx80
Intel 13900KF ~ Asus MZ790A ~ 48GB DDR5-8200 ~ RTX 3090 Ti ~ Crucial T700 SSD ~ SeaSonic TX-1600 ~ Praxis WetBench ~ Full Custom Water.