@dynamic you can try https://dir.friendica.social/servers. If you visit the server instance just click on the i for information button, usually at top right of screen and it has a list of installed addons/apps shown - mine shows at https://squeet.me/friendica. See RSS not listed separately.
I followed my RSS feed as a contact, and then chose to mirror its posts as my own feed. That's how I'm getting Friendica to show my posts in full text.