First, you’re definitely using an old version. feederRecord shouldn’t be array. Please upgrade.
jsonStringify() does what it’s supposed to do: feederRecord is an array of Strings so double quotes in there are escaped.
#{feederRecord} will merely call toString
You have 2 possibilities:
keep going with a ssv feeder, but then you have to code the concatenation yourself with a function
use a jsonFile feeder instead to you get an array of objects instead of an array of Strings so jsonStringify() can encode your values as you expect it.