I really love that style Andy, I've seen Diana Lange's stuff on openprocessing before and thought the exact same thing. It's very beautiful, apparently expressive, fragile stuff, her portraits are wonderful.
I'm not planning on bringing something like that into the controller at this time, but it isn't such a leap. Once there's a established workflow that passes the loaded bitmap through a particular processor, and produces a vector drawing out of it, then it shouldn't, in principle be too tricky. I've already converted the "webcam" tab to be a "trace" tab, and it does do that now.
Again, I'm a bit reluctant to put something with so many parameters into the controller. It might be better served by having a hot-reload option for the svg, so it would spot if a file got changed and reload it. So you would still need to hack the sketch to output svg, but you've found out that's not too hard in most cases, and from my point of view, preferable to embedding a whole lot of extra stuff in the app. And it could be pretty smooth.
Where I would be very happy to see something like this integrated is in the firmware. This is a bias I have in all things polargraph, I would always rather see the machine having some innate behaviour, rather than being used as a plotter, it's just more interesting, and (lets be honest), there are better solutions out there if you want a plotter firmware.
The big problem is that most of these kinds of algorithms work by producing a giant array of points, and then treating them en masse, and the arduino just doesn't have the memory for that kind of work.
And don't worry about wearing the forum out - just keep on coming up with beautiful drawings and all is forgiven 🙂 Seriously, it's great, and gratifying, and very encouraging to see folk being enthusiastic and getting cool stuff done, thanks!