Boy, I had a really 'blonde' moment when I started this thread. My only excuse is a heavy cold which must also have affected my brain
I own a 4000... doh.
And I guess that the paper handling is identical to the 4800.
So for anyone who wants to know, I just placed three A3+ sheets in the tray and ran off three prints faultlessly. Yes, it works well with the A4 as well.
I thought it would work because of the minimal curl on the paper. Having been through the pain of making 100 prints using the rear feed slot on the 2400 this will be quite a boon.
I downloaded the correct profile for the 4000 and repeated a print I'd made with the 2400. I found the colour match to be really astounding, the 4000 (Ultrachrome) and the 2400 (K3) prints look very similar. The main difference is of course in the gloss differential on the print from the 4000.
That settles it, I'll upgrade to the 4880 as I can print my folios in 'fire and forget' mode with this paper.