Hello Daniel, the Localized Rich Presence templating functionality was only added to Epic Online Services with version 1.18.0.4 of the EOS SDK, and has not yet been integrated with the EOS Online Subsystem plugin.
Within the FUserManagerEOS::SetPresence function, the EOS SDK API EOS_PresenceModification_SetRawRichText is used to update the user’s rich presence string.
The string passed to this function is the exact value other users will see when they query the local user’s presence.
To support templated rich text presence, you would need to either modify the plugin to call EOS_PresenceModification_SetTemplateId as per the documentation linked below or wait for the feature to be added to the plugin.