I'm still holding out there will be some improvements made to the Assembly workbench that will accommodate the weldment issue.
So far, I'm happier with the Assembly feature commands, but still see a need for improvement. As it is, modifying parts in a 3D Catia assembly does not mirror what really happens in the real world, as it should. (you cannot always design as built in assembly space)
For the most part, I prefer to do weldment design using MML, (or CCP) and boolean assemble. It's still very easy to make modifications that way, and possibly more so, seeing as how there is the lack of need for part constraints. That is, unless you use the "fix" or "fix together" command frequently.
Having said that, I must once again qualify my statements - I work in a very limited environment, usually with small scope projects. (my own company) I am not bound by the various data management requirements that a large engineering company or department may be beholden to. So consider my advice, with that in mind.
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