NanoPi M1 Plus is a good choice for OpenWRT?

After some research I found this:
I think can be a good compromise for me (price, specs, etc)

Is also a good hardware for installing OpenWRT?
In the Installation method(s) of the wiki I cant find other information, can I use the integrated 8GB eMMC for installing OpenWRT?

Thank you!

What exactly are those?

Looking at the images provided for this device, SD card is the way to install.

As frollic mentioned, it highly depends on the use case.
For IoT maybe.
But then you would be better off with some generic Linux distro like Debian/Armbian etc.

With only one LAN port and Wireless 802.11 b/g/n it hardly can be a good router IMO.