I'm currently exploring the integration of Watson Assistant with Microsoft Teams, and according to the official documentation, it seems that a Microsoft 365 E5 license is required.
Before submitting an official request, I'd like to know if anyone has tried more cost-effective alternatives - for example, a pure E3 plan or E3 combined with one or more add-ons. 
If you have tried this setup, could you please share which plan and add-ons you used and any errors or issues you encountered?

Thanks in advance, any real-world experience would be really helpful!