This is just a heads up at this stage. We have observed a memory leak running GT.M V4.4-003 Linux x86 when certain code is executed in the noundef mode.
We haven't been able to isolate what specific code is causing this yet, but removing the V "noundef" command stops the memory leak.
Just executing arbitrary code with this mode enabled does not seem to cause the problem.
I'll provide an update when I get more information about the exact circumstances.