Thank you. It occurred to me that canonical encoding is necessary to avoid random test failures, so I started with that.

I should fix support for bignums too, btw.

You were a bit overambitious with the indentation handling:

Standards.JSON.encode(({1,2,3,Int.NATIVE_MAX + 1}), 2);

(2) Result: "[\n" " 1,\n" " 2,\n" " 3,\n" " 9223372036854775808\n" "]"

It's better to not do anything there. I changed it to an alias for mpzmod_get_string.

Yes, exactly.