No, it multiplies the speed at which THE CRYSTALS are crafted.
I checked this and the crystals were still taking 30 seconds to craft, which is in line with the 2x speed boost and no other boosts at the 1 minute baseline speed for the crystals, so I don't think this is correct. The corresponding request upgrade for the yield amplifier says it multiplies yield - "x1.3 yield amplifier yield" it says- but at 100 yield amplifiers with this upgrade it still only gives 1.25x yield. It is also not crafted more quickly than expected from my global speed and does not grant more units per amplifier crafted than my global yield. (Side note, yield seems not to effect amplifier crafting at all and I only ever got 1 unit per craft). This leads me to believe these upgrades are simply not functioning as intended.