You guys may want to take a look here. This fine gent found the actual cause of the issue causing the spikes, and it’s bad terrain elevation files.
He used original files from an older, non-updated version of MSFS to create a mod that will revert the broken terrain back to pre-patch state with Asobo’s own files. And it should fix ALL the spike issues around the world, not just select areas that were manually patched up in these fixes posted above.