I have one road type bike that would fall into “gravel” categoty with slackish ht of the right length that stem up is all day and down is cx and race. Slack angle means I can push myself to fatigue in Greater comfort and stability. As yet it’s not been anything other than rapid round twisty cx courses, single-track and long road jaunts.
Compared to the road bikes i used to have (including ex-team euskaltal, and cinelli) it’s a revelation in comfort which in turn, for me, brings more speed.
Still working on the engine mind…