Andrew asks:
> A friend gave us a large slab of beech to use as the top of the island.
The slab is is about
> 36” by 45” by 3-3.5” (it tapers from one end to the other).  It is also
bowed by about 1/2”
> across the narrow dimension. ... Any words of advice?

Good evening, Andrew,
That's a lot of wasting to be doing with a plane. You might consider a
hewing axe/hatchet. This has been covered by Prof. Follansbee, and an
excellent reason to buy another tool if you don't already have a collection
of these.
https://pfollansbee.wordpress.com/2021/04/25/sharpening-a-hewing-hatchet/
should get you started