Where I worked it was normal to draw clouds round drawing revisions to draw attention to them. I would find this feature useful in QCAD but I don’t think it exists at the moment. I think it would just need a cloud linestyle to be added.
It looks like there is already a feature request for this functionality. I agree that would be a nice feature. It looks like CVH may have created something already as part of his FlexPainter tool? I have never used it but this might be worth a look.
Yes, Flexpainter works really well for revision clouds, well worth a look.
Eelie,
Linestyles can only include straight line segments and shapes that are stored like glyphs.
It is also problematic to distribute them evenly because Linestyles only have the option ‘A’ of auto centered.
Linestyle scaling is a global setting or one can change it after creation.
Seen several ACAD video tutorials where that function is in essence a LISP routine.
I think that FlexPainter with Revision Clouds comes very near to ACAD Clouds from an object. 
The free drawing form will never be supported by FlexPainter because it is a ‘Hit and Run’ on selection Addon. 
Maybe I can include global polyline with widths as painter definitions type and open up the path for the calligraphic form. 
Normally the base shape(s) is(are) retained but one can opt to remove it(all) in one action. 
Regards,
CVH