I think it also depends on riding style, terrain, and bike setup.
If you have a dropper post and a similar cleat position, than I would shoot for the same, then adjust for any differences in crank length and pedal/shoe stack height.
I used to have a hardtail and I would set the saddle height lower than my road saddle, then “hover” more often. It also gives more room to get behind the saddle when descending.
Now I run a full suspension with a dropper post, so the extra room to move when descending is less important. BUT I do use flat pedals when mountain biking, and use a more foot forward position on these pedals than on my road bike, which leads me to prefer a lower saddle height on the MTB than my road bike.