[Yaffs] Tweaking yaffs2

Is there a way to tweak RAM usage in yaffs2?
>From what I understand the tnodes tree is the main consumer of RAM.
So reducing the number of Short op caches and Temp buffers will not be
very helpful when a large portion of the flash memory is occupied with
data.

Is there a way to make the tree less detailed (smaller in depth), and
by doing so to reduce the RAM usage at the cost of more device
accesses?
Or does yaffs have to work with full trees in RAM?

Thank you