Hi,
a 1-2 sec delay is definitly very bad, and I doubt this is due to PlayMaker, if this is at the start of your game, this is likely due to assets decompressions like sounds, or big textures or meshes.
I would isolate what you think is the problem and test ( without any graphics, mesh and sounds, etc, just the logic), How many items do you have in your scrollrect?
Bye,
Jean