Pinching and zooming won’t be in an issue if a user doesn’t fight with his / her neighbor
For an asset, 2 fingers from the same hand or from 2 hands are the same.
The only limitation is related to the Text Input asset that uses a virtual keyboard. At the moment, except for keyboard embedded in a web browser, you can use only 1 virtual keyboard per scene.
If you have a specific need for multiple keyboards in a scene, contact us, we have some solutions in house.