Linksys wrt1200 usb question

I have odroid xu4 board attached via Ethernet to my llinksys 1200wrtac router.
I use xu4 for torrent seeding and downloading and as a nfs server with a external drive attached via usb3 port on xu4.

now my question is this.
If one of them dies (xu4 or router) I have to replace them and the xu4 one is 70$ and router is 150$.
where I am I cant get these parts cheaply (third world country).
so I want to know if I attach the external hdd via usb3 (separately powered) does that reduce the life time of this router and I should keep using the xu4?

any answers or experiences about usb3 on this device with constant use is appreciated.

I own a similar device (WRT32000ACM). It has a flash memory directly attached to the USB3 port, and a powered hub on the USB2 port, whith two hard disk drives and a SDR dongle connected there. It has been powered on for months with zero issues.

I do not see any reason why having an externally-powered drive could reduce the lifespan of the router.

my odroid has usb issues because the ethernet and USB have the same lane (or the same chipset,I am not sure) and heavy use of ethernet port from USB( like copying a big file on the nfs folder from itself ) will cause USB messages to appear in kernle log about resetting.

before this I use a enclosure made for odroid (cloudshell) but that one would disconnect the USB if I did the heavy file transfer and mess everything up.

any suggestion or point for me related to this issue?
nfs on openwrt on my device is doable with low cpu and RAM usage? or any other issue I might encounter?
thank you