We don't need this type of insight to act. For all its fualts, the EU does tend to have ample time between the time a law is drafted and made public, and the time it is voted on. And it's relatively clear who you need to try to influence in this period: your local government and/or president for EU Council proposals, your country's EU commissioner, and the government that proposed them for EU Commission proposals, and your MEPs for votes in Parliament, which is anyway the last line of defense.

Why and how exactly this proposed law came to exist in its current form is much harder to figure out, but that's not necessary to fully understand in order to oppose it successfully.

Yes, one round late. But some past votes they did were decisive in my vote this year.

This is the site where we can see who voted what in the parlement: https://howtheyvote.eu/

That is something you could say about almost any legislation, and it's correct to some extent. That said, politicians do seem to try and predict what they'll be held accountable for, and pre-empt that. So it's not so much the voting afterwards that potentially influences the behaviour, but the threat of doing so. I also assume that this is why contacting your representatives is important - that is, essentially, making the threat.

I'll give you that it's not a terribly strong signal.

I mean, that's how representative democracy works. You elect someone, see if they are a complete prick on a hundred different issues, and then at some point they might come up for re-election.

Another way that representative democracy works is that for many issues, you get a lot of heads-up on what will be discussed, and can influence your representative accordingly.

This generally requires coordinating your resources and efforts with other people. Lobby, protest, rabble-rouse, bribe.

Half of politics is who shows up.