Voiceflow is designed to support a high volume of users and can easily handle thousands of users a day. However, it's always advisable to regularly monitor your application's performance to ensure it's operating at its best. Each plan comes with a different amount of tokens which may be used up more quickly with a higher volume of users. So it is always advisable to upgrade your plan if you anticipate a huge increase in volume.
For more detailed information on handling interactions, you might want to refer to the general capabilities of Voiceflow's Web Chat and its integration with live agent platforms: