Hello and thank you for your reply!
I have a WooCommerce store that uses WPML to offer 2 different languages, a currency converter plugin to offer different currencies, and a VAT plugin to offer different VAT rates for customers from different EU countries.
To make the site more efficient, I wanted to create a multisite that has one subsite for my own country, one subsite for the other EU countries, and one subsite for countries outside the EU. This way I would not need to use WPML or the currency converter plugin, and I would only need to use the VAT plugin for the subsite that is for the EU countries.
But to make the VAT plugin work with my LiteSpeed cache plugin, I need to add some rewrite rules to the htaccess file, and I wanted these rewrite rules to only have effect on the EU subsite, and not the other sites.