Depends on your skills. Documentation is always useful. If you have language skills, translation of documentation or helping create language packs/translations.
That’s just off the top of my head. I’m sure if I thought about it, I could come up with more.
Admittedly, I use LibreOffice, and it works for almost all of my needs. However, I’ve never encountered the above issue, and the web versions have worked for me on Firefox. What’s your particular issue? The solution could be pretty simple; I have my user-agent string reporting Windows, and I’ve never had an issue. Maybe worth a try?
Changing the user agent shouldn’t work, but there’s a stupid amount of times that it does, and so I’ve just kept it permanent.