Fusion offers no untrim
while it offers extend, extend is not often the better approach
and untrim would be much faster
it is also a cleaner workflow
the solid modeling heal function can sometimes not solve a problem which is when you have
to go into patch mode and as a designer I rather want to have access to the original surfaces
then having to deal with what result the extend command Fusion gives me to which often are
not ideal - extend surface in general is not an ideal result (not just in Fusion).
https://drive.google.com/file/d/0Byzv_NlyKp_2WWd5NHJNNVJiQzg/view
for the sake of combining solid and surface modeling in a workflow this is a really missing tool