A question about farnesyl diphosphate synthase (FPS)

[ValWood]

Is it correct that
dimethylallyltranstransferase activity
AND
geranyltranstransferase activity (has exact synonym farnesyl-diphosphate synthase activity)

constitutes farnesyl diphosphate synthase (FPS)

and if so, both should have
has related synonym farnesyl-diphosphate synthase activity instead?

[ValWood]

we also have
GO:0033850 Z-farnesyl diphosphate synthase activity (8 EXP, 7942 total)
but I don't know what the "Z" means here and this term is not related to geranyltranstransferase activity

[ValWood]

Z" in Z-farnesyl diphosphate refers to the geometric configuration of the double bonds in the farnesyl diphosphate molecule.

is this cis?
E-farnesyl diphosphate (trans-farnesyl diphosphate)