I have another (more intrusive) patch ready, which strips
> down the PostScript file size even more by removing about
> 20 million gsave/grestore pairs per figure. I tried the
> backend_driver script and the patch seems to work. Can I
> also check this in, or should I be stabilising the
> PostScript backend at the moment?
If it passes backend driver and appears logically correct to you,
check it in. I added those 20 million pairs to be on the safe side
when I wrote the PS backend, but was never very happy about them.