Spam prevention here seems to mean the same as channel jamming. It's an interesting concept. I didn't read the linked paper, but it seems like the burned funds would need to be aggregated or a channel will accumulate a lot of tiny outputs. That also raises the point that it changes the economic incentive of the channel opener slightly. Whereas now forwarding a payment may reduce your balance, it simultaneously grants you an equivalent inbound liquidity on the other side of the channel. That would no longer be the case if bits of the channel capacity are gradually lost to the burn outputs.

It seems like this would reduce risk for routing large payments, but it could make small payments extremely costly if they fail.