Porting ASUS RT-AC3200 - My experience

Hello.
I've been attempting to port my router to OpenWrt. I made numerous experimental builds based on v19.07.3 and Master. My router has BCM4709A0 CPU and BCM43602 WiFi Pci-e card. It's not the first board in OpenWrt tree to have this CPU and WiFi card combination. Currently I'm booted of a master build. It works but I have trouble with WiFi, though interface scan works and other networks show up. I'm new at this, but I'm happy that I'm slowly figuring this out. I would be happy to receive any help or guidelines.
Here's how I did it.
So I defined a profile at:
target/linux/bcm53xx/image/Makefile

define Device/asus-rt-ac3200
  $(call Device/asus)
  DEVICE_MODEL := RT-AC3200
  DEVICE_PACKAGES := $(BRCMFMAC_43602A1) $(USB3_PACKAGES)
  ASUS_PRODUCTID := RT-AC3200
endef
TARGET_DEVICES += asus-rt-ac3200

And added a patch at:
target/linux/bcm53xx/patches-4.19/032-v5.1-0003-ARM-dts-BCM5301X-Add-basic-DT-for-Asus-RT-AC-3200.patch

--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -95,6 +95,7 @@
 	bcm47081-luxul-xwr-1200.dtb \
 	bcm47081-tplink-archer-c5-v2.dtb \
 	bcm4709-asus-rt-ac87u.dtb \
+	bcm4709-asus-rt-ac3200.dtb \
 	bcm4709-buffalo-wxr-1900dhp.dtb \
 	bcm4709-linksys-ea9200.dtb \
 	bcm4709-netgear-r7000.dtb \
--- /dev/null
+++ b/arch/arm/boot/dts/bcm4709-asus-rt-ac3200.dts
@@ -0,0 +1,79 @@
+/*
+ * Broadcom BCM470X / BCM5301X ARM platform code.
+ * DTS for Asus RT-AC3200
+ *
+ * Copyright (C) 2020
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/dts-v1/;
+
+#include "bcm4709.dtsi"
+#include "bcm5301x-nand-cs0-bch8.dtsi"
+
+/ {
+	compatible = "asus,rt-ac3200", "brcm,bcm4709", "brcm,bcm4708";
+	model = "Asus RT-AC3200";
+
+	chosen {
+		bootargs = "console=ttyS0,115200";
+	};
+
+	memory {
+		reg = <0x00000000 0x08000000
+		       0x88000000 0x08000000>;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		wps {
+			label = "bcm53xx:blue:wps";
+			gpios = <&chipcommon 1 GPIO_ACTIVE_LOW>;
+		};
+
+		power {
+			label = "bcm53xx:blue:power";
+			gpios = <&chipcommon 3 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "default-on";
+		};
+
+		wan {
+			label = "bcm53xx:red:wan";
+			gpios = <&chipcommon 5 GPIO_ACTIVE_LOW>;
+		};
+	};
+
+	gpio-keys {
+		compatible = "gpio-keys";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		wps {
+			label = "WPS";
+			linux,code = <KEY_WPS_BUTTON>;
+			gpios = <&chipcommon 2 GPIO_ACTIVE_LOW>;
+		};
+
+		restart {
+			label = "Reset";
+			linux,code = <KEY_RESTART>;
+			gpios = <&chipcommon 11 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&usb3_phy {
+ 	status = "okay";
+};

Here's my Kernel log (dmesg)
Here's my System log (syslog)

Hey welcome, and nice job.

On the wifi situation...Broadcom chips are difficult for the OpenWRT project to support

It's worth reading this page:
https://openwrt.org/meta/infobox/broadcom_wifi

For those reasons, I recommend the Asuswrt Merlin project instead for Asus routers. However you could also try Freshtomato

I've been successfully using OpenWrt since then. 2.4 GHz works fine, 5 Ghz is tricky. Direct firmware loading and clm_blobs are all naughty. I'll go and commit now =)
Considering AsusMerlin I used it before for a couple years, I guess it's a solid. But I really want OpenWrt.
Some of the problems I've had with wifi are connected to NVRAM settings, I think.

Good to hear, however, 5Ghz will always be tricky, and this is due to Broadcom not supporting open-source software like Openwrt, like I said