My usual recommendation would be to use the WCS as equipment coordinates. It really doesn't matter if the plant layout changes as you just move the equipment XREF in the host model as required. It does help to have the same orientation for profile and isolines, but not mandatory.

Trying to get people to do that is another story. Most will insist on plant coordinates regardless of the extra work to handle changes.

Dimensions and annotations are delayed as long as possible, although the title block, notes, etc. can still be set up.