Please bear in mind that the .htaccess file you have found does not include front-end and back-end protection for Joomla!. It's best to nit-pick the additional features you want and add them as custom .htaccess code to be added at the top or bottom of the file.
Also bear in mind that you MUST NOT include sections of code which perform the same function as an existing .htaccess Maker feature. For example "Error prevention", "REWRITES", "Forcing `https://`", "Suppressing / Forcing the `www.` at the beginning of URLs", "File access", "Block access to all hidden files and directories", "Block access to files that can expose sensitive information", "HTTP Strict Transport Security (HSTS)", "Compression", "ETags", "Expires headers" will definitely conflict with .htaccess Maker. I've not tested the other sections, I can't tell you if they will work or not.
Some sections rely on Apache features which may be blocked by shared hosts. In this case your site will display an error 500 or blank page. Please do not request support for this situation :) Once you add custom code to the .htaccess Maker we can't provide support for it (unless "please remove all custom code first" sounds like a support option, because that's the first thing we'll ask you to do).
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!