Both applications use the .htaccess file to provide a link-shortener, thus the web-server has to read the file on every access or update.
To my understanding OLS can only import it and needs to be restarted in the process.
I'm no authority here, but OLS does need to be restarted to affect a change to .htaccess. Litespeed Enterprise (the paid service) can apparently do it dynamically, without a restart.