Multiboot you have now been activated. Try to write the image to a USB flash drive and run from it (activate multiboot NO longer need, You already have it enabled).
Yet I have no options. If You are familiar with Linux, you can run Armbian and there to run all the tests to find a working configuration. Then it can be transferred to the LE.
Unfortunately Im not quite that familiar with Linux, probably the limit of my help is flashing my second usb drive with test images to check if they work or not. I dont drasticaly need bluetooth or wifi so Im pretty happy with the current image as it all runs great.