But this is not hot patching, at least not if I understand correctly: changing 30 to 3 was not meant to have an effect on the running script, it was meant lower

But this is not hot patching, at least not if I understand correctly: changing 30 to 3 was not meant to have an effect on the running script, it was meant lower the waiting time for next time you're running the script. This is not an unusual thing to do in other situations. I'm sure you change your code all the time while an instance of the program is running, no matter whether it's compiled or interpreted. At least I don't habitually close a stop program first before I make changes to the source code. The example in the article shows that that's a bad idea in bash scripts because they, unlike other code, don't get read in entirely (as in, say, Python, Perl, etc.) before they get executed.