Personal opinion: best time to buy a smartphone is when you actually 'NEED' it. So perhaps, narrow down on what your requirements are and when do you actually need a phone. If K40 Pro meets those requirements better and you can wait, I'd say wait. But if you need a phone right now, no point in waiting. Technology changes rapidly and anything you buy now will get 'outdated' in 3-4 months any way. And this is not specific to k40 series or Mi 10T, this applies to all phones in general.