Thanks for the info. Sounds like you've found about the same limit I have with --max-nodes and -Xmx4000m. This weekend I'm going to add a --max-areas parameter. Setting this to a number < 255 should allow for higher a --max-nodes value with the same heap size. In your case with 367 areas, setting --max-areas=184 should allow for a higher max-nodes setting without any extra passes required.
Tested this latest version on my American extract with -Xmx4000m:
With 1.2 million nodes the Java VM crashed due to lack of memory. Using 1 million nodes the split succeeded with 367 areas in 3:20 hours. Some swapping was noticed (bad for speed). Although I'd rather use the 1.2 million setting, as that is a nice balance between the number of failed map builds and map size worldwide, using 1 million now enables me to do all the work myself instead of relying on others. Great, thanks a million!
Next up: splitting the whole world on my laptop and process the output with mkgmap. See which areas need fixing manually...