g1smd - 8:57 pm on Dec 13, 2012 (gmt 0)
You should run a couple of tests after every change. Once full stop or bracket out of place can bring a whole site down.
I did mean "big file". I have seen a htaccess file with more than 6000 directives in, some time ago. There was little chance of making sure all the code was correct nor of modifying it without breaking something.