I ran a 32 meter prior to this 42 meter and the 24" pads were adequate in nearly all cases, but this 42 has pretty much double the outrigger load and the 24's are never enough on the pour side.  I've made some 42" pads and they seem to do the trick.

How big are the pads on larger booms?  Do you carry your own extra dunnage, or are you scavenging on site?

I may start to carry 48" 4x6's for the times I need a bigger footprint.

that will help keep most out of trouble

You might want to go 6" by 6" anything smaller won't hold up at that length. Just my experience.

All of the pumps I've ran and seen on the smaller side of 50 meters have had the 1x1 meter pads as they come with as standard and also 8 pieces of 6x6" also in 1 meter as standard.
For extra on a 40M+ I like to carry 8x extra 6x6" in 1.5 meter, any more I don't bother with, need the space for other stuff
and if the site is so bad it requires more it usually is too bad to set up on...

48" or better heavy wood spool ends...the kinds used to spool heavy cable...are really good.  The good ones are staggered when nailed together and easy to move around the jobsite.

Spool ends - that's a good idea.

I have a set of the 36x36x2 inch DICA pads on my 47,And I LOVE them.Those paired with the 24x24 wood pads work REALLY WELL,I carry 4 of the wooden 24x24,6 of the 24x24 DICA's,And a couple LARGE pieces of wood (just for elevation)...So all that coupled with the 36x36'es I have never been "In need" of any thing more