External lightmapping - disable Unity's UV patching (5.5)

Hi there,

as many others, I want to create lightmaps using an external tool (so our interactive and pre-rendered visualisations line up and we can use familiar tools as far as possible). Now, by using some scripts from this forum I got Unity (5.5) to load my pre-rendered lightmaps onto the correct objects.
However, Unity applies its own UV layouts from LightingData.asset (which I’ve previously built while experimenting) for lightmapping whenever I start play mode. So I do see my own lightmaps, but they’re all over the place.
I can keep Unity from messing with my UVs by removing LightingData.asset from the slot in the Lighting pane (I verified by using a custom shader). But once I do that, lightmapping seems to be disabled in the standard shader. So the way it is I can get either lightmapping with messed up UVs or correct UVs without lightmapping.
Can I somehow have both and keep using the standard shader or should I just switch to custom shaders?

I found the solution here:
Problems with instantiating baked prefabs
Thanks Johnny10. I suspect that assigning the value from the editor to LightmapSettings.lightmapsModey is somehow skipped when no Lighting Data Asset ist found. Dear Unity Team, please fix this!