The chips don’t actually read the ink level. None of them do, not even the Epson chips. It’s just an estimate. Epson chips are extremely conservative about this to avoid running dry, at the cost of a significant amount of ink often remaining in the carts when the chip reads empty.
Before getting the resetter, I felt lucky if a negative printed entirely without a “cartridge error” (the actual message I get on the 1430, may be different on other printers) during printing. Sometimes the cart needs refilling sometimes not. But the message means that the cart has automatically reset and now needs to be pulled and replaced so that the printer recognizes it.
You can anticipate to some degree when a cartridge will reset by checking ink levels in the Printer Utility Status Monitor before printing. If something shows close to empty, whether or not it actually is, there is a chance it will reset during a print. Unfortunately, the only way to avoid this is to use a chip resetter.
My advice is to always top off all the ink cartridges before a printing session, and to use the chip resetter at the same time. Do not rely on the ink level indicators to be accurate. Keep track of your own ink usage so you know what to expect. My work uses shades 4 and 3 more rapidly than others, then 5 and 2, and finally 6 and 1. Yours may differ.
I know this is a nuisance, but it is the price of circumventing all the obstacles that Epson throws in our way for using 3rd party inks.