You're the only one who owns that device at this point, therefore you'd be the only one who could do the porting.
Don't blindly assume that the devices would be compatible, just because their hardware is roughly similar. Usually at least the hardware ID and very often the flash partitioning will differ even on otherwise identical devices - and trying to force-flashing the wrong firmware has a huge chance to hard-brick this device.
and do some soldering - the serial port are probably the four holes by the smaller of the two shielded chips.
unfortunately it's also very common for tp-link to cripple the serial port access, forcing you to not only solder the pins/holes/connectors, but also do some additional soldering.
Soldering is easy for me. I have the implements to do it. Bad thing here is need to buy a serial cable for doing "some experiments". It's a pretty expensive router here (everything is expensive here indeed)
I don't get it, it's a powerfull device, very stable conection, very powerfull signal, 2 bands, and nobody ported OpenWrt or any other firmware for this one??
(everything is expensive here indeed)