I still dont think these look like athecate hydroids, they look exactly like a Nausithoe species in OP's pic and the others in this thread. mine haven't stung me like OP though...
If you want to keep your hydriods, keep them. But in some aquariums they take over and kill whoever they want. Corals, and anemones cannot fight back. Thriving hydriods want a territory, they are going to win.
Advice is to get rid of them for a reason. This isn't cancel culture.
Having a variety of animals in our aquarium creates a war zone. It's our job to keep it in check.
If someone wants to observe and see they are of no issues in their system. Thumbs up to that person.