I have tried it multiple times and always end up throwing the can away. It takes a lot of effort to get a professional finish (automotive quality) compared to what technology provides today, a thousand years after the Egyptians used it. It takes too long to dry for sanding the seal coat, it does not scuff sand fast and I find it almost impossible to spray an automotive quality finish without sanding and buffing after spraying. The durability of Shelac on its own is an issue, does not handle water or food stains at all. Most think it is compatible as a seal coat for anything else. Not true.
Any professional pre-cat or post-cat finish available today will beat Shellac hands down in all aspects.
Why play around with multiple seal coats and a final coat, if the entire job can be done with only one seal coat followed by one final coat? 15 minutes between coats and a very light scuff sand after the first coat? Then have a durable finish which is stain and nail polish resistant.