dimensions adapted to non-straight lines

A correspondent writes:

I have noticed an aesthetic issue when a line is defined, e.g. wavy, dancetty, potenty: because this means that the field division average is maintained, but the actual aesthetic borders of the field are not, centring no long looks centred. An example will make it clearer, I hope:
A blazon I am working on, which cants on my wife's surname, is:
Purpure seme-de-lis Argent, on a lozenge Or a horse salient Purpure, on a chief potenty Or three archers Purpure.
Now, if I take out the "potenty", the archers and the lozenge are each vertically beautifully centred. With the potenty, of course, they are still centred from the _real_ margin, but not from the visually apparent margin, and so it looks like the archers are too low on the chief and the lozenge too high in the field. I could edit the SVG exports, and will probably do so sometime if I can get my brain to function well enough, but the majority of users will find that beyond them. Is there any chance you could incorporate this in calculations (perhaps as an option)? Of course it also raises another question: simply recenter to an effective margin, or also reduce the dimensions of the charge accordingly...?

The issue does not name any files, tests, or entry points. Begin by locating the calculations for field divisions, charge positioning, and non-straight line geometry, then determine how an effective visual margin should be defined and whether charge dimensions should change. Done means the requested centering behavior is specified, implemented, and covered for the cited line types.

Written by the indexing model from the issue text.