Thanks for sharing this, mate. Such a model would be the one to follow among Blockchains that aim to scale indefinitely like Bitcoin SV. Penalizing spam attacks would make the network more secure and resilient like never before. I believe that costs would rise within the Blockchain as the attacker tries to spam the network with thousands of transactions. In the end, it wouldn't be worth it at all to try to disrupt the Blockchain as it becomes too costly to do so.
I've never thought for once that Monero had such a model for scaling. Dynamic block sizes will allow the Blockchain network to adjust its capacity according to network load. With its penalty fee, spam attacks would be a thing of the past within XMR.
Now, the real deal would be with fee-less Blockchains like EOS and Steem as they would encourage spam attacks sooner or later. Without a proper penalty mechanism, these Blockchains would be rendered insecure and completely unstable as they become flooded with thousands of transactions made by a single attacker.
Nonetheless, it's interesting to see how the outcome of scaling massively for Bitcoin SV turns out in the future. If successful, then I believe that other altcoins will do the same. Otherwise, Bitcoin with its Lightning Network would become the norm for mainstream micropayments in the safest way possible.