OpenWRT on Mikrotik

RouterOS General
1

The RouterOS IPv6 support is not enough for me, so I need Linux kernel 4.x functions. The OpenWRT 18.06.2 use Linux kernel version 4.9 or 4.14.
I found a list, which devices are supported: https://openwrt.org/toh/start?dataflt[Brand*~]=MikroTik

How do I install OpenWRT?
How do I reinstall the RouterOS if I don’t like it? How do I save the original license key? Other important?

2

This is not an OpenWRT forum…but you can export / import licence through system menu.
Regarding install check their forums, but probably some variation on netinstall process.

3

Most devices (exclude ARM based) are more or less supported…
Switching between ROS and OpenWRT is not the much work…