Have object "stuck" to another without parenting?

We have an object which sometimes moves with delay in relation to another, but sometimes is fully stuck to it and moves along with it. For ease of handling, there is no constant parenting-unparenting happening, but the object simply has a script with bool attached to it; when true, it will softly lerp-follow, when false, it will always set itself exactly to the position and rotation to the other object (which happens to be the SteamVR controller).

However, even when the update routine immediately sets itself to the transform position & rotation of the other object, there is a tiny bit of a delay (perhaps 1 frame, though it feels like a bit more). Is there any way to make this following instant?

So, one way I found to get this working is to use the camera’s OnPreRender() to call the object in question’s position update.