We shouldn’t even need to bump, nor should that be possible.
Maybe feedback could be categorised. People will be able to pick the category of the type of feedback they want to find. Posts that were created within the past week will stay at the top. Only after that can they be pushed down by newer posts. The posts will only be in their assigned categories, meaning they will only be pushed down by posts of the same category.
These are a couple ideas. They could be refined, but it’s a good starting point.