I'm debating about whether to enable zipmax internal compression or not.

If I'm using: 2 pass 7Zip + BJWFlate + deflopt
what are the odds that the internal compression will make any difference?

Also, I suspect that BJWFlate may be failing on very large zip archives (85MB+).

I'm using the sample command line you provided in the zipmax.ini...

packer-exe-3 = bjwflate.exe
packer-cmd-3 = -a -n -s64 -r -y %1 %2

Could one of the command line switches be causing the problem?

If not, could it be a problem with not having enough physical memory? I have 1GB on my machine but I notice that almost all of it is used during either bjwflate or deflopt (I can't remember which).