Randomly teleporting players in your Iris world can cause performance issues, but there are two great options that use very limited server resources.
RTP plugins will always use server resources. Pregenerated worlds however, take much less effort to randomly teleport players in.
If at any point you run into an issue with either of the plugins, please try contacting their support. If they cannot or will not fix it, let Support know, so we can update this page.