I tried it, and it was wonderful! Actually I tried it twice, and the first time, I had my timing wrong so my lump was barely going on a reverse sear (took longer in the oven then I expected) so it was still hot, but not my usual scorching hot. It seared nicely, but I went a tiny bit longer than my usual two minutes on each side. The depth of flavor was wonderful, with what I think is the celery seed shining through with an aftertaste.
The next time, I seared it over high heat, and while still good, I noticed that the depth wasn't as pronounced. Is it because I acclimated? High heat blurred some of the flavors? I did not burn the steak, but there was a tiny bit more charring, but nothing out of the ordinary and definitely not at the burn stage. And the funny thing? I used only a little rub the first time, and a lot more the second.
I'm going to try for a lower heat sear again and see if that makes a difference.