I am currently using a 0.4mm nozzle. Out of the large corner pieces that I have printed so far, I have only had one permanently fused together. It was the first piece that I printed with a bronzefill filament. That filament had a lower melting point, so I had to turn the temperature down and slowed the printer down a little. Also make sure that you are doing at least two perimeters with your slicer set to print the perimeters from inside to outside since that provides more adhesion for the overhangs.
Most of my large corner pieces were stuck together when they cam off the printer. Some popped free pretty easily. A few required me to hold the piece in one hand while firmly tapping the center circle with a pair of pliers to break it free.
Given that others might have problems with the aggressive overhangs in the captured part of the large corners, I have made some adjustments to the pieces to reduce the overhang in the captured part of the large pieces. I am test printing one now and will upload those after I test this one. Should be in the next couple of hours. I'll add an update to the info when I do.
Thanks and please post your make when you finish it!