Is it possible to flash u-boot via tftp (trying to unbrick TP-lInk td-w9980)

I'm trying to unbrick my td-w9980 via serial console (bricked after installing most likely wrong firmware via web interface hack). One of the steps is to flash u-boot.
I've managed to connect via JTAG via Raspbery Pi 4 which has this weird issue with it's serial connection getting corrupted - part of the hack was reducing Pi's clock speed to solve this, but after running for a minute the connection starts to getting corrupted. Obviously don't wanna send firmware over serial.

Was wondering if it's possible to do so via tftp - it's already possible to overwrite routers firmware via it, perhaps it can be done for bootloader too?

Or perhaps I can just skip u-boot upgrade altogether?