These CPU vulnerabilities are generally only reproducing under very controlled conditions and scenarios. Yes they're there, but they're next to impossible to exploit on a regular chaotic system. I really wouldn't get too hung up about it.
Spoiler differentiates itself by being very easy to exploit (even as simple as running some malicious javacode in someone's browser when they visit a website), and very fast - it works in seconds, and makes existing rowhammer attacks easier to perform as well. Its nature makes mitigation very difficult, at extreme performance loss, or indeed - as the researchers suggest - impossible. I'd definitely consider that something to get hung up about, tbh.