These extra command lines come with the Zoners reference, but you have to go backwards and get a copy of 253 before the custom builds to get the extra refrence information.
-sparse
Enable low memory vismatrix algorithm
The original vismatrix algorithm was limited to 65535 patches due to its design. Its memory usage also grew exponentially with the number of patches (patches * patches / 16 bytes). This option enables a compressed vismatrix, which at the cost of extra CPU time, breaks the 65535 limit, and also uses about 10% of the memory the vismatrix would.
-extra
Turns on 9 point oversampling for lighting, making it look much better.