Deemed profit for partnership firm

In A.Y. 2015-16, a partnership firm has filed ITR-4 (maintaining books) with NP, Salary to partners and Interest on Capital amounting to 12%. Now for A.Y. 2016-17, firms can show deemed profit of 8% or more (by filing ITR-4s) and also claim interest on capital and salary to partners from it. Now is it advisable to show deemed profit restricted to 8% and claim interest on capital and salary from it, for A.Y. 2016-17. All this keeping in view that from A.Y. 2017-18, this deemed profit of 8% will exclude interest on capital and salary to partners. Can IT Department, raise this objection of showing less net profit margin i.e. @ 8% in A.Y. 2016-17, while it was 12% net profit margin in A.Y. 2015-16, when books were maintained?