Shared hallucinations may be an “actuality”, as they influence action, yet there is only one independent existential reality.

Fire.

You cannot think feel or believe your way out of burning.

Thoughts feelings and beliefs are however we cope.

This reminds me of research on deaf communication and sign language.

Deaf culture includes very complex norms about eye gaze. When someone is using their hands, for example, things need to be aligned so they can both work and see the signer. The signer will position themselves for this.

This implies gaze is shared and linguistically mediated.

Similarly with object avoidance. There's what we might call a protocol, part of the pragmatics of ASL grammar. When walking side by side, Deaf people advise their conversational partner of objects outside the other person's peripheral vision. This seems to occur automatically and unconsciously in the same way the rest of grammar does.

It superficially looks like telepathy. The person who cannot see the object they are about to walk into just steps around it gracefully with no apparent interruption in the conversation. Notice the footsteps are synchronized: https://youtu.be/EPTrOO6EYCY?t=382