Hello, thanks all for your feedback.

- spiro + pattern on path with circular pattern + sketch crashes

This works at rev 18773, last week, the sketch effect was broken.

- moving a LPE in the list up or down cannot be undone, and if you
undo, it undoes some previous action and crashes soon after

yes indeed, LPE are not very undo-friendly for the moment.

I've put online our project final report.

You can check it out, we wrote it in english. It is a description of our work, our organization...
The best would be to store it on inkscape.org. It could give ideas to other students.

I added things from this report to the wiki :
- Calculating the groupbounding box for people to build LPE using the bounding box of the item on which the LPE is applied.
- examples and details to see how existing LPE work

Steren