The 'All In' button positioning and size make it easy to miss-click and require the bid session to be cancelled and started all over again.

It doesn't feel like all-in is that much of a central option compared to manual bids.
It would probably be better if the button was smaller and positioned towards one side/corner of the window.

In fact it is used quite often thus it was like that for few years and this is the first time I hear this request. I'll continue to monitor it but for now I do not plan any changes.