Map 84 is a vanilla map.
Since this is a partner level, it is a very bad idea to try to jump over the wood. The only time that can be possible is if someone is not attached to a partner (which happens when there is an odd number of mice, OR when there is an even number of mice and the Shaman has the "Solitary" skill. It is possible to survive the repulsion wood if both mice hold jump the entire way across, and do not clip the side of the lava before trying to go above it.
The shaman can build a bridge over it. The bridge can either be very close to the wood to prevent it from flinging far away, or far away to prevent touching it in the first place. More often than not, the mouse attached to the shaman will kill them both, causing the rest of the mice to try jumping it.
The shaman can also put one portal on the ground in front of the wood, and the other at the same height on the wood. When you walk into the ground portal, you can continue walking on the wood without getting hurt. The only problem is that your partner has to walk into the portal at the exact same time as you or you will both die, so this could be a dangerous method.
The shaman can also put boxes on top of the red trampoline. As long as they are placed on top of the trampoline, and not in the air, the repulsion will not take effect. The problem is this takes a fair while to set up, by which time many people could have already died; or trolls can hit the sides of the boxes and not jump on top of them - making them fly off. Alternatively, two large planks can cover the whole trampoline quickly. Sometimes, the planks will be flung off the lava ground if they are not nailed to the background.