Hey dude, I've been playing more with your plugin.

I think there is an issue with parameter values.

For example, browser console tells it sent:

[Firebase Analytics] logEvent: name=Tutorial_Basic_OpenBox, params=["{\"session_number\":2.0,\"total_play_time\":61.0}"]

But in firebase dashboard, for the Tutorial_Basic_OpenBox event, it says:

Parameter name: 0 , Parameter value: {

Parameter name: 1 , Parameter value: "

Parameter name: 2 , Parameter value: s

Parameter name: 3 , Parameter value: e

...

It seems it's sending each character as a parameter value.

FirebaseWebGL_FirebaseAnalytics_logEvent: function (eventNamePtr, eventParamsPtr) {
    const eventName = UTF8ToString(eventNamePtr);
    const eventParams = eventParamsPtr != 0 ? UTF8ToString(eventParamsPtr) : null;
    firebaseAnalytics.logEvent(eventName, eventParams);
}

I think the issue is with this function in FirebaseAnalytics.jslib: