The question is simple. I have been researching and in similar questions I have not found the answer. Should defer be used in a script loaded at the bottom of the page? Would it be redundant or does it make sense in any situation?
Browser will parse the document from top to bottom, hence putting the scripts after all the main content will make the parser to reach that <script> later in time; which make the browser to download the script later in time; The delay caused by putting the defer in the bottom is absolutely non-sense, since the browser won't execute them (<script defer>s) before (or during) HTML parser;
Thus it's better to let the browser load ( download ) them (<script defer>) as soon as possible, an have them available to execute as soon as the all the main tasks are done.