Note that wp-config.php does not normally change after initial installation of WordPress, so if what they say is true, that would be the easiest place to add the code.
I’ve never heard of doing this before, and I’m not sure where you would add that – probably at the end. Try it to see if it works. Would be much simpler than a child theme. And if that suggestion is true, then you should also be able to add it using Weaver Xtreme Plus actions and filters exactly as is.
Plugins load before the theme, and that plugin has apparently defined a global variable that can be set from almost any point in a theme or other plugin, or even in the wp-config.php file which would load before almost anything else. Very unconventional approach to the “WordPress way” of doing things.
Well, @GR8FL, I did a bunch of testing. I’m not positive, but I think something had gotten broken in the notification system. I was trying on a test account, and was not getting emails. It IS possible it is still broken for gmail accounts, but the notifications got through on my last attempt using both the @ notation and the Notify me of follow-up option from under the reply box.
So, I think you should see a notification now, maybe 2 if you also checked the notify me box. But if you don’t, I’ll try more tests to gmail accounts. You should also check your spam folder.