Calculate Tax over ride at PO level

Dear All,

There is a client requirement, that default tax calculated at PO level to be override say for 5% of the cases. Tax rule setup is on the basis of domestic procurement and product inventory. Appreciate if anybody pls let me know. Already raised a SR.

Secondly: They don't have Order Management. They have on project. So AR transactions are created mainly from projects and some manual transactions. For manual transactions they need tax to be calculated from memo line. For this requirement what would be suggested solution.

Is it advisable if I set tax code at memo line and set a determination factor say: