mDash notification complete

I am testing mdash with several esp32 devices , it works great!
I have two questions of Client Library:

  • How to detect that the notifications sent with mDashShadowUpdate & mDashNotify(“DB.Save”,…) has finished? my device is low consumption and must go to sleep after sending the data, I had to add a delay of a few seconds before going to sleep to wait for the sending to finish.
  • How can I send an array var of 1Kbyte? Should I use a json object?how?