How can I model in world coordinates when I am working in SOPs?

try using the construction plane
(r-click on the c-plane button
for orientation options).


-cpb

If you want to see all the other objects in the scene while you model, just toggle on the “See one/all” button at the bottom right of the viewport. It is the one that either looks like a tiny red pyramid (this object only) or a red pyramid on a blue grid (see all other objects as well).