Here’s a link to a post on a similar topic, long story short from most peoples experience, google cares less about global limits and more about velocity, like lots of repeated calls in a very short time.
They also like it when you send larger containers of single messages with many requests over repeated message calls with single requests in rapid succession.
But these are just ‘likes’ and ‘dislikes’ noticed by people using them, the limits are kind of a black box.
That is to say, they are probably posted somewhere, but they never seem to match reality until you push too hard and they suddenly snap into place, making them guidelines and not really limits.