As an enterprise company processing hundreds of projects with rates tied to them, I would like to have a central place to log multiple time-boxed or time sensitive rates available at the company or user level, not just the project level that we currently have. (The multiple rate functionality we currently see at the project level would meet our needs if at a higher level like the company or user ). This would reduce time to entry, reduce errors and missed rate changes, and improve vendor relations.
Ideally, each user has a rate with effective dates for that rate. The rate could be entered in advance of the date. E.g. Update a new rate on a user in mid-December that is effective on 1/1 of the upcoming year. The hours entered for that user use the new rate for hours entered 1/1 and later.