[Not a bug] language define conflict

The Admin page modules.php has a Switch which, depending on whether you select the Payment, Shipping, etc. modules, the php sets:
define('HEADING_TITLE', HEADING_TITLE_MODULES_SHIPPING); - or whatever title is relevant.

However, while an "echo HEADING_TITLE;" right after that line causes the proper title to appear on the page, the actual header spot is incorrect if you have any Extra language definitions which include a define('HEADER_TITLE'...) in them. Right now my Shipping Module/etc. pages have a header title of "Email Address Export for Newsletters".

IF I delete that extra language file, I end up with "E-mail Archive Manager", etc. for every extra language file with that define in it.

I'm not sure why this occurs, but that's the only page I've noticed it on so far. I assume it has to do with the HEADER_TITLE being defined in the module.php file, rather than a separate langage file like most other Admin pages, but I'm not sure why, after it is defined in the header (and my echo properly shows the right title), it then resets to the external definition in the body.

That's not a bug. That's just the way things work.
If you don't want things to load out of order, put your language files in the appropriate folders ... noting that the extra_definitions folder's files all get loaded, hence impacting the order.

So you're saying that extra_definitions is not where definitions for extra pages should go? (bearing in mind that I just put the files where the add-ons/plugins had them).

Is this different than extra_configures, extra_datafiles, extra_functions, and extra_boxes? Or should those files be somewhere else as well? Thanks

If you're referring to the Email Address Exporter mod, it doesn't tell you to put anything into an "extra_definitions" folder. The language file for that mod goes directly into the language folder, exactly as it's included in the zip.

I appologize for my own error. I guess when I installed these plugins, having seen so many other plugins put files in that folder (legitimately, I assume? I'm not sure), I got into the assumption that the folder was simply there for organization purposes (as a place for add-on files to keep them separate from core files), such as the custom template folders on the front-end side. I must have thus put a those three languages files (as it turns out, only three) in that folder, assuming the designer of the plugin simply chose not to use the folder for organization.

My bad, thanks for taking the time to clear up my mistake :)