Could we have an optional chart overlay allowing those of us using stylus capable tablets to mark up a chart at the planning stage with notes, arrows, highlights etc. much as in the same way one can scribble on a laminated paper chart with an OHP pen.
I see it being essentially a transparency ‌‌‌‌which would allow simple mark-up using the tablet's stylus with a simple set of features such as choice of stroke thickness and colour, an eraser and a 'wipe all' option.

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