Interestingly, I was doing the similar stuff for 3 years to a US company. Curious, is your client a legal tech company? Mine was.

The experience helped me to roll out an API, as https://extracttable.com, for developers.

OCR tricks? Assuming post processing dev stuff - may I know your OCR engine. We are supported with Kofax and openText along with cloud engines like GVision as a backup.