Hello @TC-10031428-0
Cost accounting is a module where you can replicate your books of accounts to allocate indirect and overhead costs down to a granular level — cost objects, cost centers, departments, or even individual products and services — using flexible allocation rules.
Your Implementation partner might have commented that “it is not a good fit” because It's designed to pull data from GL, budgets, and statistical drivers, run allocations, and produce management-accounting views — typically run periodically (daily/weekly/monthly batch jobs), not transaction-by-transaction in real time.
Also automation of invoice generation is not possible by cost accounting module. You can try to achieve the automation of invoice generation by Posting Sales Invoice Batch job and explore if you can utilize some of the filters to fulfill your business requirement.
Regards
Aayush Tiwari