Workaround for Google Geocoding API restrictions? Why no HTTP referrers?

I have a subscription for Location Manager Extension.

Wordpress: 5.4
GeoDirectory Core: 2.0.0.90
GeoDirectory Location Manager: 2.0.0.25

According to the GD Docs, the Google Geocoding API Key “must not be restricted with HTTP referrer rules.”

I have discovered if I use any HTTP referrer rules, I receive map error messages like
“No Records Found
Sorry, no records were found. Please adjust your search criteria and try again.”

If I remove the HTTP referrer rule, everything works fine.

Here are my questions:

1. Why must the Geocoding API key not be restricted? Google warns that without HTTP referrer restrictions, you may be exposed to key theft or misuse as the key is exposed in the HTTP page source.

2. Is there a workaround or other method to prevent potential Geocoding API key exposure in this way? Is the Geocoding API key exposed in the page source or other places?

3. I am posting this request in the Multilocation Add-on forum, although the extension is called “Location Manager”. Should this be corrected?

Thank you,

Mark Murphy
Herndon, VA
US