Security of Find My Device for Pixel Lineup?

Hey all, I have heard around the start of this month that the Pixel 8 series and thus almost certainly all future Pixels will have the “Find My Network/Device” feature. My question simply is since this feature has not been open-sourced, and the fact it runs even while the phone is turned off, what threat does this pose to privacy/security if any at all? If you were being tracked by someone, would this theoretically be a security flaw?

Edit: I should mention I’m more on about it’s security while running GrapheneOS as obviosuly running stock OS is a much bigger privacy risk than this feature.

In terms of privacy, I’ve read that it’s a nightmare, nothing surprising with Google, but I couldn’t explain technically why.
The GrapheneOS team has also announced that this feature will not see the light of day on their OS due to privacy and security concerns.