For wifi I accidentally able to get full speed (80MHz ~ 867Mbps) when booting via the clover from https://github.com/the-darkvoid/XPS9360-macOS/commit/c7149ab350682310bf2c091bc0a082cc8f9b66b8.(I was using this repo until my DW1520 break). I'm able to boot by just having brcmfx-driver=1 and added pci14e4,4353 device properties. After boot up I saw that wifi interface was using AirPortBrcmNIC.kext instead of AirPortBrcm4360.kext and I'm able to get full wifi speed, but the system was getting freeze and hang very often especially when it's consuming high bandwidth 700-800Mbps for long periods. Do you guys have any suggestion? b/w I'm back to 40MHz for now because it's very stable and 300Mbps is not bad at all.
Open Config.plist with Clover Configurator
Under Devices, go to Properties, look for PciRoot(0x0)/Pci(0x1c,0x02)/Pci(0x0,0x0) and delete it
Go to Kernel and Kext patches, and enable DellSMBIOSPatch
Add AirportBrcmFixup.kext to /EFI/Clover/kexts/Other for wifi
Add BrcmFirmwareRepo.kext & BrcmPatchRAM2.kext to /L/E for Bluetooth
Repair permissions and rebuild cache