Unless the 10mS delay is actually required,
For example, the 1mS is necessary in the code below:
/* Initializations */
// ------------------begin ESP8266'centric----------------------------------
WiFi.forceSleepBegin(); // turn off ESP8266 RF
delay(1); // give RF section time to shutdown
system_update_cpu_freq(FREQUENCY);
// ------------------end ESP8266'centric------------------------------------
I have a few other ESP8266 projects over on my page:
https://www.hackster.io/rayburne/projects
Ray