how often are you checking a project CAD file - start, middle, end or just the end or in the middle? The end may be too late but sets precedent for similar work
our files are on a server accessible to all drafters
Usually at earlier target submission QC dates, (35% submission, Design Development, etc.) to have everything fixed before going too far, so "start to middle" I guess.
Then usually not again unless something obvious shows up.