Yes, but if you have NO header blocks added in ISPCONFIG, you can use the header file directly.
In cases that it's not a production server, just for personal uses, it might be easier to copy/paste the above header_check.
However, I understand your point and if entries were being made it would be a conflict.
So, I would recommend doing what Till says if you're already using that feature or may use that feature.
ISPC3 on Debian! It's great!