How much memory may a HPPL program use on a G2?

[komame]

When you enter a command and press ENTER, it gets executed. If you then press ENTER again immediately after completion of task (without entering a command), it will execute again, and each subsequent press of ENTER will trigger another execution. This is not the same as repeatedly copying the command (in that case, you see the command on the left and the result on the right for every line on the stack). I'm mentioning this because when I run the CROSSWORDS call with TEVAL measurement in this way, it often happens that each successive execution produces a better result. This improvement continues for up to around the 30th run. I don't think PPL has any caching because, in that case, I would expect the second run to be faster, but the third, fourth, and subsequent runs would have the same speed. This effect is such that several consecutive calls result in a better outcome with each call.
   
This is repeatable for many different cases, but sometimes it takes more calls for Prime to enter this mode. Once it does, each subsequent call is faster.
@Jeff, do you have any idea what might be causing this?