Can you teleport farther away with misty step if you have a double from Invoke Duplicity? The Channel Divinity feature says:
you can cast spells as though you were in the illusion's space, but
you must use your own senses. (PHB 63)
If you were where your duplicate is, you could step to a space 30ft from its position. So if it is 60ft from you, you could teleport to a space 90ft from your actual position. But the spell says that:
you teleport up to 30 feet (PHB 260)
This would put a hard limit on the distance you can travel.
Which rule takes precedence here?