Hi @Icarusradio,
In my case, I've done some hacks in a WR941ND v3.6 to be able using USB.
This router is almost the same as WR1041ND v1, but this one has a particular register value set by u-boot code:
ar7100_reg_wr_nf(AR7100_USB_PLL_CONFIG, 0x00001030); /* Reg Addr: 0xb8050008 */
So, with this little modification on my u-boot code I can use some USB devices with 19.07.4 / ath79.
Using 19.07.4 / ar71xx I can use USB too if I change the board initialization code on Openwrt source (files mach-tl-wr941nd.c and dev-usb.c). It's not necessary the u-boot modification.
I don't know how or if it is possible to express this kind of initialization using DTS yet. If I understood well, it depends on some driver expecting and being able to use a configuration expressed in DTS file...
But, I'm not sure which driver could have this responsibility. Maybe ar7200-usb-phy?? (created by 0004-phy-add-ath79-usb-phys.patch).
I my case, the probe fails with the same message as yours (the same for some others devices - some posts have this message...):
ar7200-usb-phy usb-phy: phy reset is missing
I'm not sure what is the impact of this failure... I don't know if it could affect you...
The driver is not loaded, but in my case I can use some (not all that I've tested) USB devices.
Good luck!
PS: There are some specific threads about ath79 migration. Maybe you could ask there for more information. At least, there are a lot of people that knows a lot more about this than I 