Thats interesting when i select help-->contents and search for
"wavescan.trace" it can find that anywhere.
If i search on "line" I do find
viva.trace lineThickness tring "fine" nil
Which when i place this in the cdsenv file changing the fine to bold and correcing the misspelled "tring" it doesn't work until you remove the "nil" from the back end.
This works from the command line,
envSetVal("viva.trace" "lineThickness" 'string "medium")