It's just one question survey. It will take you no time at all:
https://www.surveymonkey.com/r/CGFHBGB

We can display edited story. We can export edited story. But whatever we do, your source story in Gdoc will have to be changed by you manually. This survey will tell us how you plan to change your main source after you see the suggested fixes in the program.

7759326 It's been a week and here are the results:

I wish there were more responders to the survey. You can still fill it out if you haven't yet.

Here's the thing. Currently, option a) is supported and is the easiest to implement. That's also pretty much how the competition works:
http://www.grammarcheck.me/
http://www.reverso.net/spell-checker/english-spelling-grammar
http://www.onlinecorrection.com
http://www.spellcheck.net/
http://www.slickwrite.com
http://www.paperrater.com/free_paper_grader
http://www.writersdiet.com/test.php
http://hemingwayapp.com
http://www.polishmywriting.com/
http://spellcheckplus.com/
https://app.grammarly.com/
http://www.expresso-app.org/
http://www.webpagefx.com/tools/read-able/
https://virtualwritingtutor.com/
https://www.grammar.com/grammar_check.php

The other option that is apparently used is c) which uses Word. It wouldn't be trivial, but it's probably technically somewhat possible. However, I doubt that many people use both Word and GDoc to edit their stories.

There's nothing wrong with the program having multiple features, but I can't implement all of them alone. I need help from the community. I need help from you.