Gravatars vs Avatars
I don't understand why you have chosen to use gravatars over avatars. Most people using forums are used to uploading their own custom avatar for each different forum they use. Not having this feature is bad for user retention.
wpForo has three different avatars:
- Upload Custom Avatar
- Use External avatar URL
Please navigate to Your Profile > Account subPage and find avatar settings.
Also please read wpForo Documentation here: https://wpforo.com/docs/root/members/
Excellent! I don't know how I missed this!