It seems as though relying on something a bit more verbose, such as the guidance from Nielsen Norman Group [1], might be more effective in helping people building software.

In particular:

> 0.1 second is about the limit for having the user feel that the system is reacting instantaneously, meaning that no special feedback is necessary except to display the result.

[1] https://www.nngroup.com/articles/response-times-3-important-...