I do sympathise with that a bit, but for me at least it does not look like jql is the solution:

    '|={"b""d"=2, "c"}'

this appears to be something like jq's:

    'select(."b"."d" == 2 or ."c" != null)'

which.. is obviously longer, but I think I prefer it, it's clearer?

(actually it would be `.[] | select(...)`, but I'm not sure something like that isn't true of jql too without trying it, I don't know if the example's intended to be complete - and I don't think it affects my verdict)