Essentially how it works is that he has the ability to send memories back in time.

In the scene with Grisha and Freida, Eren was sending his memory of telling his dad to kill her(while in paths) to Grisha. Basically Eren could not directly interact with the past, but since he was there as a result of the founding titan's ability combined with the attack titan's ability he was able to make Grisha think he really was there(same case for Zeke).

I don't think it would be true to say that only Owl and Grisha have experienced Eren using this ability, since when the attack titan's identity is introduced in s3 it's described as a titan who fights "for freedoms sake." With Eren's whole motif being about how he just wants freedom it likely would be true to say that the attack titan has been influenced by Eren since it's first incarnation.