FYI, as I know I’ve mentioned before, I’m working on a significantly improved Google Maps integration. Before I submit anything officially, I’m testing out the changes in a “custom component” repository. I will probably have something ready later today for anyone who’d like to try it out – even though not all the documentation is in place yet, and it might still have issues – and provide feedback. I’ll provide the repo URL when it’s ready. I’m willing to “hand hold” anyone who’d like to try it. 
FYI, it still has the existing “legacy” tracker implementation, so after switching to it, you should see no difference, except for a warning that says the legacy implementation is deprecated. At that point, you can “add” the integration the usual way via the Integrations page in the UI. It will create new entities (that shouldn’t “collide” with the existing, legacy ones), so you can see how it works side-by-side with the original.
Here is what I have implemented so far:
- Add UI-based config flow, including reconfiguration via the CONFIGURE button.
- Enable or disable creation of the tracker entity associated with the registered account. Note that this entity is lacking some info (full name, battery level, etc.) Trackers are still created for all people shared with this account regardless of this setting.
- Can use existing cookies file if found (which eases upgrading), but also includes a file upload feature that makes adding/updating cookies much easier. (I.e., no confusing file renaming and figuring out how to get the file onto the system and in the right place.)
- Read and display cookie expiration date in config flows.
- Create a repair issue at startup if cookies will expire in the next four weeks.
- Check cookie expiration during normal operation (not just at startup.)
- Initiate reconfiguration flow when cookies expire (either at startup or during normal operation.)
- Save & restore state during HA restart or config entry reload (which also happens when new cookies are loaded.)
- Enhance error checking & handling. (Hopefully) no more uncaught exceptions in the log!
As implied above, I still need to work on the documentation. I also plan to test out the cookie file creation procedure on Chrome, Edge & Firefox, and include details instructions for each, possibly even including them in the UI config flow.
Note, unfortunately, there doesn’t seem to be a way to do the authorization directly in HA, so the annoying step of grabbing cookies is still required. However, I’m trying to make that as painless as possible.