Straight up, the old romance publishing imprints are dead for this. Anything with 'historical' or 'category' on the cover tends to sand down the edges. I practically live on the Kindle store now, but you need to hunt. Typing 'why choose romance' or 'dark academia romance' into the search bar works better than generic 'strong female lead' because the algorithms for that just push mainstream stuff.
Specific authors build whole universes around this vibe. K.F. Breene's 'Demigods of San Francisco' series has women who are legitimately powerful, not just sassy. The erotic tension comes from them having real agency—they choose the risk, they navigate the consequences. It's a different kind of spice when she's driving the action versus being swept along. My library's a mess of dog-eared Kindles because once you find one author who gets it, their 'also by' page is pure gold.