Maybe I'm the only who missed this change, but I noticed this line in the wiki:

Additionally, starting with version 2.1, the rocket silo animation speed scales with the quality of the silo. Although it's not mentioned anywhere in the game UI, this means higher quality rocket silos have higher potential throughput. Note that quality is the only thing which affects the animation speed; modules and beacons only affect the crafting rate of the rocket parts.

That's so awesome! I hastily created a legendary rocket silo so I could test them side by side. Here's the animation (sorry for the distracting unpowered lights...)

47.39% faster according to the wiki

That is so awesome. What a great addition