Thanks for the links.

Adding the delay in my code will not work in the case where a log message is being sent that is longer than 25 characters (MAX_PAYLOAD). The library code for that method splits the message and sends them in a loop where I have no control in my program via the wait() method.

I think in my case, I will add some code similar to what was suggested in the github discussion, but I will add it to MyTransportRF24.cpp rather than at the top level send() method.

Something similar to this:

#ifdef MY_TRANSPORT_RF24_MESSAGE_DELAY
unsigned int lastSendMS;
#endif

bool transportSend(const uint8_t to, const void *data, const uint8_t len, const bool noACK)
{
#ifdef MY_TRANSPORT_RF24_MESSAGE_DELAY
	unsigned int waitTime=lastSendMS+MY_TRANSPORT_RF24_MESSAGE_DELAY-millis();
	if(waitTime > 0) {
		wait(waitTime);
	}
#endif
...

Haven't tried this yet, but it should address my issue for now.