I've interviewed people in my job, and most people read from notes on their monitor (it's easy to tell). It's not a bad thing at all - may as well make the most of the tech. Reading fully written answers is just an extension of that, and a reasonable one for you. Also, with a stutter, we have a bit more leverage than we tend to realise. You could either tell them you're doing it up front (frame it as an accessibility measure), or explain it that way if they question it - but I don't know why they would in all honesty. Honestly my main bit of advice would be to pace yourself. If you need a moment to breathe and think, take it. As long as there's some visual cue to show that's what you're doing, you're fine (e.g. looking up, 'ummm', etc).