Many Mountain bike forks, now, have the fork crown a pressure casting
of molten aluminum, around the fork and steerer tubes, in manufacturing,
and so cannot be removed.

If you have a Heavy abuse Down hill type fork with double crown ,
above and below the headset bearings, bars directly bolted to the upper
instead of a stem.
then the triple tree concept, can more be applicable,

Very early Rockshocks forks had clamp on crowns, but that was 20 years ago.