Well, I managed to circumvent the issue with the ShowConfirm/ShowPrompt by overriding the CSS for positioning with !important... there's some fixed <style> tag attached to the iwNotify ID in the html body. Ultimately the problem seems to be how the browser see's it's size (or calculates the % into a coordinate) because the html IW creates is simply width and height in percentages which should (and do in other contexts) draw properly. Interestingly if I look at JS properties like clientWidth or viewport width, they report properly. So I don't think this is IW's issue, other than I couldn't find a way to SET the left and right position at design time and have it be reflected in the browser...beyond adding in raw header html. Anyhow, that ones sorted.
As to the modal window, I'm not sure yet if I can add header script to get past the issue there, playing around in browser dev tools trying to figure out how/where this positioning is happening, I tried a similar strategy but the way it redrew the modal window was not what was expected.
As to the version, we're too far into QA to switch up a core component like this at this time (nor am I convinced it actually would work if this is a browser issue). So we need to find a workaround for what we have at the moment. Otherwise, everything else is working great, this is more-or-less the last thing in terms of drawing anomalies we need to address.
As to the modal window, I'm not sure yet if I can add header script to get past the issue there, playing around in browser dev tools trying to figure out how/where this positioning is happening, I tried a similar strategy but the way it redrew the modal window was not what was expected.
As to the version, we're too far into QA to switch up a core component like this at this time (nor am I convinced it actually would work if this is a browser issue). So we need to find a workaround for what we have at the moment. Otherwise, everything else is working great, this is more-or-less the last thing in terms of drawing anomalies we need to address.