I have a couple of problems with Holdos Hyperspace manoeuvrer/tactic, there's the one that everybody's talking about i.e. as why hasn't it been used before etc etc etc.
However my problem is more basic involving the science fiction about hyper-drive that is to say people are always (in Star Wars certainly) making the JUMP to light speed which as I understand it means one second your in normal space the next your in hyperspace although in the films they visualize this with spacecraft zooming of into the distance my understanding is that there is no actual acceleration as such as you literally JUMP into hyperspace without needing a 'run up to'
So when Holdo fired up the Hyperdrive she would have just jumped straight into hyperspace? And not gone 'through' anything? Possibly my understanding is incorrect but as I see it the tactic doesn't even fit in with ANY science fiction.
The scene could have just as easily been done I think with Holdo setting the Hyper-drive generators/engines to maximum/overload and with all guns blazing to make a hole in Snokes shields ram/explode her ship in close proximity achieving the same effect without breaking canon.