Hi @anton, welcome to Mender hub.
I’m not clear on what you mean by “local install”. Can you clarify?
As for embedded storage, we have a number of platforms using eMMC if that is what you are referring to. The mechanism for imaging to that device varies based on the board manufacturer but generally involves some mechanism to have the device connected over USB to your laptop and then have it appear as a USB mass storage device. You can then use “dd” or equivalent to write directly to the storage.
As for compiling from source, you certainly can do that and if it’s working for you then all the better. We have a utility called mender-convert that can modify a stock device image to be mender compatible. You can find details about the latest version of this tool here: New iteration of the mender-convert tool
Hope that is useful.
Drew