This is a fairly simple and repeatable bug. The title of this report suggests that it only applies to Size simply because I haven’t tested it otherwise.
I created a ParticleEmitter inside of a part within the Workspace. After that, I ran this code from the command bar:
Although that made me think the order mattered, it’s something stranger. That first sequence actually creates a NumberSequence that has value 0.4 both at t0 and t1.
Doing NumberSequence.new(1,2,3,4,5) will act the same as NumberSequence.new(5). It seems that internally, it always use the constructor with one argument, using the last argument. (probably cuz stack[-1] in Lua C)