That won't satisfy the IVA examiners, It has to be 'permanently' locked.
I have just helped someone through the test. We adjusted the brakes so that the fronts came on just before the backs by jacking all four wheels off the ground and turning the wheels by hand with the brake partly on. We drilled the nuts for the roll pins but not the bar then took it for the test . When the examiner was happy with the balance of the brakes and after a failure (which is inevitable) we took it back to the re-test with roll pins fitted. The examiner was then happy.
Brian.