Plex ratelimit

[BLACK4585]

Hey,
I just discovered the program and now want to use it to sync my Trakt progress and lists against a big Plex library. My Plex Account is limited to 1 stream at a time.
I configured the program so that first, all my progress in Plex is overwritten by the Trakt progress.
It begins syncing, passes the first library with 101 media contents and then gets stuck at the next library with 2049 media contents at element 591 every time. I get an error message 401: Unauthorized. If you are interested in the whole stacktrace, lmk.

Could this be related to a firewall blocking the many requests at one time, or does the program use multiple users/agents which could trigger the Plex rate limit with 1 stream at a time?

[BLACK4585]

I just ran a test, disabling the mentioned first library, but the sync progress stops at 591 media contents of the second library anyway.
Could this indicate that Plex (or the library) is interfering then?

[BLACK4585]

I suppose this could also be a rate limit by the Plex API, as assumed before, as they might not like 2k requests in 30 seconds.
Thus, I would prefer to convert this into a (feature request) issue, since a cooldown in between different libraries and every 500 synced items or so.