Fixed caliper

I don’t know if anyone has asked this but I can’t seem to find an answer.
Is there a reason Toyota’s 4pot fixed calipers only have one spring on the pins from the factory?
A lot of brake pad kits come with top and bottom springs yet Toyota only uses a bottom from the factory. I’ve never felt a difference between one or two springs.
Any answers?

 

I just did my pads and rotors. Don’t really have an answer for you but my springs looked like the picture in post #248. I put it back together exactly the same. With this picture as reference, maybe others can chime in.

https://www.tacomaworld.com/threads/diy-front-brake-pad-change.38025/page-13

 

Just an ant rattle spring that sits at the bottom, it doesnt change wear properties.

Venzas and siennas etc use 2 but honestly I wouldnt over think it.