If I’m doing a presentation, I try to line up the time blockage to account for what I think will be the discussion that ensues.
I line up the time for the discussion I want to happen.
The goal of a presentation isn’t to whip through it and have no questions, it’s to generate dialog and next steps. Sure I might ask for people to hold off questions until the end so they can hear everything that is being said. But that doesn’t mean we are stifling the conversation, it means there is a great deal to cover.
Presentations are at their best when questions and conversation is generated, it’s what takes them from being “okay” to being “great”.
Otherwise, start all your presentations with, no questions, ever, the end.