I read somewhere in the middle of the thread about Ã* post processing Cura plugin to calcul a bounding box for auto leveling.
I think it's a good idea to use the gcode "G29 Lx Rxx Fy Byy" to optimized the auto leveling only on the area which is used for printing.

So the idea is to write Ã* Cura plugin which get the min and max value of X and Y in G1 commands in the first layer and add the G29 command in a specific area of the start gcode.

Sorry if it's not clear (my English is bad)
Sorry if I'm out of subject, I was looking for people speaking about that and this thread was the closest i found.

My goal is to share my work and improve it with your help.

Feel free for asking more informations

Regards