Update to 10.0.2 - some HSTS questions

Before update to 11.0.2 I’ve had a working HSTS setting in my .htaccess after update I was warned to set a proper duration. So I did edit my HSTS settings again. While editing I discovered a line DO NOT CHANGE ANYTHING ABOVE. Maybe it was there before but I ignored it. This leads me to this questions:

Everything below that line will remain untouched during updates?
Did my former settings get lost because they were located above?

I’m not sure, somehow you would expect it but there is also reason not to do it. I normally keep a copy of modified files because between major version are often changes, some improvements I did myself are already included or some tricks don’t work any more.

Ja you are right. It’s a good habit to keep track of all modified files.