In WED, File -> Build Map -> there are
Tesselate shaded:
Tesselate flat :
Tesselate turbulence:

but in the manual,
they are:
Tessellate shaded
Tessellate flat
Tessellate turbulence

So it may not easy for people to search in the manual.

You're right - I believe tessellate is written with 2 'l', so the map compiler dialog must change.

Both versions are correct, but I agree that in both places the same spelling should be used.