The TBAO add-on has some exciting options for us to be using and playing with. However, there is still a lot of functionality missing 
I love that we can “toggle” on new custom fields that pull in data from the project budget settings (estimated costs, actual costs, budgeted hours, etc.). However, we need to be able to also have a field for the difference between estimated costs & actual costs, as well as estimated hours vs. actual hours. If you use the Asana fields that pull directly from the project budget, you cannot use them in a formula field in order to create a custom field that calculates the remaining time or remaining costs.
I know we can use a rollup field if any of the data is stored in tasks inside of the project – but we need to be able to put the estimate in the project budget and then have the difference to the actual time entered. This is significantly important!!!
Please help me vote for this 