Well, I bought the one stating 0.3 seconds. But obviously didn't get what I bought.
Also, I can't seem to find any 1.54" display on the Waveshare product pages that has 0.8 second refresh.
Anyhow I noticed using my setup and code with a button triggering an interrupt and then updating the display, that it's about 5-600 ms for the actual display update to happen, but then it's another 300-400 ms for the call to return.
So I need to make sure I get the right product when ordering more.
Thanks for the help!