Adding support for Linksys E5400

They were blowing out the Wifi 5 inventory at my local Meijer (regional grocery store - like a midwest Target), and I picked this up for around $20. I looked up the chipset (MediaTek) before I bought it, and it seems to be a duplicate of a few other devices:

https://deviwiki.com/wiki/Linksys_E5400

Related models/identical on the inside:
Linksys E5350/E5300/E2500 v4

It seems to have a MT7628DAN inside for SoC, secondary wifi is MT7612EN.
I believe I saw 7628 wasn't supported in the past but that has changed recently.

I haven't connected serial to it yet but I am curious if there was a guidance on getting support added to OpenWRT? Not sure if the bootloader is locked down or if the firmware is locked down like recent Linksys models.