What drawbacks would there be in drawing miniaturized patterns in a vector-image program and then scaling them up?
Can you scale them up directly and get a perfectly workable pattern just by doing that? Unlikely, unless the pattern itself is particularly simple (a basic skirt or loose-fitting garment).
But can you do it? Sure. You'll need to accept that, once you've got the overall idea worked out, you'll have to make some further adjustments in tailoring after scaling up--your pattern won't be &quot;done&quot; by any means after increasing the size, but you can save some frustration on working out larger elements of the pattern using smaller pieces of fabric and less sewing time before bringing the whole concept up to full scale--keeping in mind that drape and gathers may not always work as well in the small-scale versions and may offer some &quot;surprises&quot; when you scale up.
I don't draft patterns myself, but I'll regularly modify existing commercial patterns to fit what I'm trying to make, and I generally will test the modifications in small-scale first before moving into the full size pieces. As long as you're aware of the limitations of the process, and the adjustments that need to be made when switching scales, it's perfectly doable.