however: i'm sure you are aware that the donecanvasdialog message is
part of a "private" API, that is: it is used for the internal working of
Pd and users are not supposed to use it directly (even though it allows
you to do nice and handy things).
so i don't see anything inherently wrong with the new behaviour.

is there a "public" version of it? as this is very important for some of my abstractions and very useful, specially jp.menu and jp.preset, which simulate a drop-down menu only using Pd mechanics.

you could always send an [editmode 0( message to the parent patch, to
inhibit the problem.

theoretically yes, but when being used in abstractions (which is my particular case) it makes things harder to determine what is the main patch window where to send the message to. And make it dependent on an external library that will find out the main window name.

Joao