Hi there,
Thank you so much for getting in touch, we really appreciate your time.
Unfortunately, this is not currently possible as it would require different core functionality to be built into to support this sort of feature.
This is something I Will kindly take note of though for our lead developer to take a look at for possible implementation in a future version of WP Google Maps.
My apologies for the inconvenience.
Kindest Regards,
Steven De Beer