It seems to have had good confidence or energy to dig in.
Uh, a video, nice, I look forward to seeing your aquaria.
I have a powerhead sitting pretty low above the sand, so my main concern have been to make sure the anemone didn't wander anywhere near that and get sucked in.
It seems they move at night, but in little steps at a time, unless current is strong enough to make them start drifting.
Did you see any reaction from the Euphyllia after you slowed flow? I would not advice you either way, since I have too little experience with the technical gadgets. I don't know if your flow is forty times stronger than I am used to and all that, and I would hate to give you bad advice so the video is a perfect suggestion.
And I get to look at a video of your tank, and for some reason, I completely love looking at everyone's tanks, aquariums are just such a wonderful hobby.