Performance of transform.localposition vs transform.position

Hi,

I am currently working on a tank track system which changes position of each pad by using transform.localPosition, it works fine on my computer but I will sell it through assest store, so I try to optimize it for the sake of the future customers.

The problems is the numbers of access to transforms is huge, e.g 320 pads for a tank each frame, and I don't know is there any different in using position/ rotation vs localPosition/ localRotation? I will do a benchmark, but any insight will surely help. Here are my questions:

1/ The more sub-level the localPosition/localRotation is, the slower the code runs, because the more matrices it needs to multiply to returns the world position/rotation, right?

2/ What is the best way to change position/rotation of a large number of objects?

Thanks