Feature description

I've been experimenting with firefox pdf output on documents with a lot of big images,
and found out that currently the maxPayload is limited to 256MB (the generated PDF was 320MB).
Changing that limit allowed the PDF to be obtained.
I understand that this is a edge case, and also it seems that some experimental bidi API will one day allow to properly stream the result instead of passing such a payload in one big chunk.
Nevertheless, it would be nice if it was possible to change maxPayload using connectOptions.