How do you handle purchase invoice data entry for clients — still manual?

I'm a software engineer working closely with CAs and wanted to understand the ground reality better.

For those managing purchase registers for SMB clients:

1. How are you currently extracting data from purchase invoices (PDFs/scans) — manual entry, outsourced, or any tool?
2. How many invoices does a typical client send per month?
3. What's the most time-consuming or error-prone part of this process?
4. Have you tried any software to automate this — what worked or didn't?
5. Has a client ever lost ITC due to data entry errors or missed invoices?

Asking because I'm exploring whether automation here is actually useful or if existing tools already solve this well. Would really value honest opinions from practicing CAs.