I've been tinkering with my DW1820A serial CN-096JNT and other BCM4350. I put in device properties and BRCM kexts in kext/other. I found out that if you go to BIOS>Wireless>Wireless switch> and turn everything OFF, also in BIOS>Wireless> and turn WWAN OFF, and enable just WLAN and Bluetooth, the freeze/lag is gone, and WiFI and Bluetooth work fine. Hope this helps you.
When I reboot my Dell E7450 the startup gets very long and stucks at some point. Then I have to manually shut down the laptop, and turn it on again. Then it boots properly. So the issue is that whenever I restart it from the Mac menu the boot gets stuck at some point. I use config.plist from Mojave bootpack, and kexts from screenshots. config.plist.zip