For now the vectrex C setup uses the complete toolchain Peer build. This means after the compile stage the assembler AS6809 is called (instead of assi, which is the internal assembler of Vide).
AS6809 is called with following options:
-x Hex listing (default)
-p Disable automatic listing pagination
-l Create list file/outfile[.lst]
-o Create object file/outfile[.rel]
-y Enable SDCC Debug Symbols
-g Undefined symbols made global
These options can not be altered.