That’s an interesting combo, assuming that you mean an R2000, because I have the opposite - an R1900 (previous model of the R2000) for Piezo and a 3880 for colour. I have this combo precisely because of the issue of pigment sedimentation.
It’s relatively easy to deal with in the R1900. I’ve been tracking it recently, and I start to see a little drift in linearity after four weeks, even with reasonably regular printing. By about six weeks I need to do something. With this style of printer I can either drain the carts back into the bottles, shake the bottles and refill the carts, or simply remove and agitate the carts. This latter approach seems to work, and I confirmed it by measuring linearity before and after. The theory is that in this style of printer, regular printing is supposed to be enough to agitate the carts and keep the pigment in suspension, but that’s not my current experience.
A 3880 running Piezo is trickier, because while you can (and should regularly) remove and agitate the carts without triggering a head clean, there’s still the 10-15ml in ink in each ink line to worry about. The only way to prevent sedimentation is to print regularly, and if you don’t then sooner or later you have to run power cleans to purge the lines, wasting a lot of ink. I recall Walker suggesting that sedimentation is less of a problem with the newer inksets, but I know of one forum member who had issues with K7 in a 3880.
Does shaking the entire printer help? Some older posts here suggested that it did, but this was later clarified to refer to the very large former printers with large ink carts, and not the 3880. I’m therefore not convinced that less rigid racks would help that much. See here:
I suspect that IJM staff will disagree with what I am about to say, which is that I use a 3880 with OEM inks for colour because in my experience and that of many others, sedimentation is a non-issue, unless perhaps you leave a printer for years. I’ve been measuring the performance of mine over several years through periods of varying use and there’s been no drift.