It prevented me from launching, switching or killing any apps or rebooting the phone. The phone was entirely unusable until I figured out how to reboot. That's more than visual. My impression is that is was memory only, but it was extremely suspicious. It’s quite possible that data was exfiltrated.

Simply locking up Springboard with a DoS doesn't necessarily mean your were breached on the device. It's more likely that nothing came of it, exfiltrating data would involve breaching a lot of sandboxing and we'd be seeing a lot more chatter about that honestly.

Sure, there’s been no evidence of anything wrong since then, either with my phone or related accounts. Apple did fix a couple 0 days with more serious implications shortly after this, but it’s not as if I or a random search result website would be worth someone using a 0 day.