Idea: Abandoned Structures

I know there are a few events relating to abandoned buildings, but I feel like there's still more that could be done with finding old ruins on alien planets. I had a few ideas for things that could be interesting finds.
I have two ideas for buildings to find: Standard Template Construct Manufactories, and Orbital Defence Grids. The buildings would have a rare chance to spawn on a habitable planet (with potentially a higher chance of spawning in Fallen Empire-owned space, or on Tomb Worlds) and could be repaired by a special project.

STC Manufactory: An ancient manufactory that optimizes production efficiency. Once repaired, grants a planetwide bonus to build speed, building cost, and reduces consumer goods consumption.

Orbital Defence Grid: An ancient defence array. Increases garrison/fortification health and reduces army maintenance.

I also feel that it would be cool if Fallen Empires could have repaired versions of these on their core worlds and ruined ones on the habitable worlds in their space, to give them a little bit of extra flair. It could really show how they're 'fallen' empires.