If you read my earlier post, that's what I was indicating. What's interesting is that your experience has led you to ask about companies where client-billed travel has more friendly/generous policies than internal.

IME, I've actually seen the opposite. My company's internal/default policy is quite often more generous than our clients' policies, but when we bill to clients, we must abide by their rules. For some discrepancies (as a more everyday example, this often happens when a client bans alcohol from meal expenses) my company will make up the difference by allowing spend according to our internal rules but only charging to the client those expenses which align with the client policy - my company simply makes up the difference when reimbursing the employee.