Epson has changed it's systems several times, so it depends upon the
printer model.
The printers keep track of three basic pieces of information:
1) Waste ink pad ink amount
2) amount of ink left in the cartridge (intelledge cartridge or status
ink monitor or both)
3) time between last cleaning cycle which may move around depending on
last startup.
To my knowledge, the cartridge chips themselves are not responsible for
the storing or actuating that part of the equation, but instead, in
firmware and some memory, but I could be mistaken.
Are you sure they aren't claiming that with their cartridge chips, the
printer will not read a cartridge low or empty, which would trigger a
cartridge replacement and the larger purging process.
A regular head cleaning may use between 1% to 3% of the ink, but major
purges like with the printer when brand new, or the cleaning between may
mean a lot more up to 20%, as I recall. Cleaning for changing
cartridges is probably about 5% of the ink or so, but it's out of each
of the cartridges, so that adds up/
Art