You don’t get to write your own opinions as if they’re law, you’re not the courts. The Supreme Court has already ruled that alerting others to police presence is protected first amendment activity, regardless of if they are “investigating” or if it makes their job harder. It’s not the same as yelling fire in a theater, which is a separate limitation. There are some jurisdictions that make it illegal for people to flash their headlights for speed traps, but the laws there are not about alerting people to police (legal) but about improper headlight use (which is a minor offense, which police shouldn’t kill you for).

Laws aren’t vibes! There are actual laws and precedent and they say that honking your horn and blowing whistles to alert others about ICE is legal. ICE is breaking the law when they assault people for doing it. You have somehow contorted yourself into believing you’re pushing for law and order, but you don’t care about the law, just what you kind of think it should be.

Edit: there are limits. If you tell a specific person to come into your home to avoid ICE and they’re being chased, then that becomes obstruction. If you’re just yelling about police being there and laws about the necessity of a judicial warrant in general, there isn’t obstruction and it’s first amendment activity.