If you store your list as a string to one of the sequence variables, u, v, w, you can half the size of the entire thing.
Then, if you need to evaluate it, run 'u' and Ans(X where X is the list element.
The only issue with this is the lack of editability if that's a word.
That's neat.
I don't use complex numbers for compression because I don't see anyway to make things smaller with them.
Use also the fraccional part of imaginary part?
You can save 4 integer numbers in every element.
Other thing to compress is if you use number smaller than 1000 you can save like this:
E3A+B
To decompress:
int(L1(1)/E3)->A
L1(1)-E3A->B
where the E is the small E. A and B to numbers to save and are smaller than 1000.
This could allow easily 8 numbers in one element...