That's not generally how the legal system works. If you've disabled the duplication filter, and then generated substantial amounts of duplicated GPL code and then violated the GPL license, a judge is not going to say "Well, fair enough, you used the loophole of copying code through an LLM, after all." They're going to treat it as a willful copyright violation, the same as if you'd just copied and pasted it.
And again, I have to ask: why? Why would you think that putting tons of time and effort into tricking the model into repeating memorized code is going to be a better investment than just using it normally to implement the functionality you want?