At work I create some fairly large and (overly?) complex documents some of which
contain over 100 complex plots (from oocalc - included, not linked per corporate
requirement), twice that many tables, indices, appendices, etc. ad nauseum, the
largest running to about a thousand pages. Let's ignore the fact for now that I
should be using a master document for docs like these.

The memory limitation on the graphics cache
(Tools>Options>OpenOffice.org>Memory>Graphics Cache>Use for 
OpenOffice.org.) is a problem.

It is fixed at 256 MB.

I would really like to be able to raise this significantly - say up to 2GB if
necessary.  I have Linux machines available with up to 4GB of memory (and one
with 16GB), so "using up all the avilable memory" would not appear to be an
issue. (I could try this in windows, but I don't really use ms products, so I
have not tried it.

I would really love to see a feature - set the default max at 256 MB maybe, but
let the user raise it if he checks a "Yes, I really understand the consequences
of what I'm doing" box or some such.

Justification: on large documents the scroll speed can be extremely slow as
(apparently?) objects are being dumped out of the cache and new ones created, etc.

Aside: previously I tried doing these as master doc's with sub-docs, but
converting back to word '.doc' fmt for the corporate sycophants (who only look
at the pdf anyway) bombed every time - so that really isn't an alternative.