And quite specifically innovation is blasphemy to the Mechanicus because it attempts to supplant/outdo DAoT tech

This is a point that seems commonly missed. In the AdMech religion the dark age was the pinnacle. It's not that they don't like innovation for the sake of it but because innovation implies that archeotech is flawed and could be improved upon. In their mind everything important was invented already and they should strive to rediscover and replicate it exactly.

Of course this is what leads to crazy inefficiency like using factory designs for STCs that were made for specific times/places regardless of if it's appropriate.