I used the usb variables from the khadas-vim3. Booting on usb worked ok but if booting from sdcard it didn’t detect the usbdisk that was in the usbslot . Had to take it out and in again to get the disk detected. When using the usb variables for am6.dts the disk is recognized at boottime even wen booting from sdcard.
I don’t know why wifi will not work for you, but for me I get:
5.869143] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43752-sdio for chip BCM43752/2
[ 5.869475] usbcore: registered new interface driver brcmfmac
[ 6.122240] Bluetooth: hci0: BCM4362A2 'brcm/BCM4362A2.hcd' Patch
[ 6.281298] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43752-sdio for chip BCM43752/2
[ 6.522104] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM43752/2 wl0: Dec 4 2019 01:55:28 version 18.35.387.11 (wlan=r853831) FWID 01-ae9dfd3b