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is there an actual roadmap proposed in how to filter those transactions?

No, there are only some ideas, related to dropping historical data. Which means, that no matter if something is a real payment, or some kind of data push, it can be stripped in a similar way. And then, transaction makers are mostly unaffected, because usually they care only about the final destination of their coins, while data pushers will cry, when they will find out, that less and less nodes are willing to share their pushed data, when they start providing proofs, instead of sharing original data pushes.

In general, when you start a new node, and you synchronize the chain, you don't have to know, that "Alice -> Bob -> Charlie" is what happened. The only thing you have to know, is "Alice -> Charlie", and a proof, that all signatures are valid, and are covered by the heaviest Proof of Work in existence. And then, Bob can locally keep the proof, that he was inside, but nobody else needs that during Initial Blockchain Download (in the same way, as nobody needs all Lightning Network transactions).

And then, if you have just some money-related transactions, it is not a big deal, that Bob will have only some local proofs. It can be even viewed as an advantage, because then, payments can be more private, if all chains of unconfirmed transactions will be simplified every 10 minutes, while charging the same fees as usual. But in case of any spam-related activities, these users wouldn't want to keep their NFTs locally. If they would want to do that, then they would use commitments today. So, they will suffer the most, if that kind of changes will be accepted by the community.

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Because all I read are "let's vaccinate the blockchain" posts.

Read about proposals like SwiftSync: https://groups.google.com/g/bitcoindev/c/FpSWUxItXQs