Magma_block player damage

**Is your feature request related to a problem? Please describe.**

I'm trying to avoid contact damage from magma_block's in a certain world

**Describe the solution you'd like**

I would like to turn off player damage by walking on magma blocks used in water elevators
If there is such a way, please advice.
If not: is it possible to implement as contact-damage or a flag?

**Describe alternatives you've considered**

I thought it could be done by enabling `disable-contact-damage`. Tried every player-damage setting. Read about every region flag but I couldn't find an appropriate way to avoid player damage done by magma blocks

**Additional context**

WG 7.0.3