In the forthcoming AX 2012 R2 Cumulative Update 6 (which, oddly enough, will be the one after CU1), we added a small feature to the Ledger Posting Setup in the Project Management and Accounting module. You can now specify the main account for project revenue postings based on the sales tax group. This was requested by customers in places where not only are they required to report the taxes paid to the municipality, but the revenue associated with these taxes as well. This support already existed in the inventory module for sales orders and purchase orders so we added it for project invoices. It will apply to any project transaction (hour, item, expense, or fee) that has a project sales tax group specified.
In the example above, invoiced transactions with the sales tax group CA will be posted to 411200 while those with the sales tax group MA will be posted to 411300.