Project costs - Labor Issues

Hello, looking for some advice on best practices.

We are a heavy project centric organization - our business is doing projects for clients to make money! We have Project costing, billing and project management installed, along with OTL.

We do not have the project or the task segments in our GL chart of accounts.

Historically we've been running all accounting processes with the goal of putting ALL charges related to a project cost center into the Projects module. This works mostly fine with other costs (AP, PO etc). However, when it comes to Labor, since only time sheets come into Projects from OTL, it's always a pain to figure out what the non-OTL costs are and which correspond to which project (and task) and upload them into the Projects module using spreadsheets. Again, this is done with a view to having 100% of costs sitting in any project related cost center to have that