Gary is right here.
No he isn't. There seems to be some confusion about the anti-third party cartridge technology built into the latest Epson ink cartridges in these new SC-P series printers, perhaps including the maintenance cartridge chips in the Pro printers, and the waste ink arrangements in the P600.
The P600 is different to the P800 and all the Pro Epson printers. It doesn't have a maintenance tank, so there's no waste ink chip to reset. It has waste pads at the bottom of the printer. The printer has an algorithm for determining how much ink has gone down the waste ink tubes and into the pads, I assume from the number of head cleans, and how much waste ink the pads can hold. Once the magic amount of ink is in the pads the only official way to keep using the printer is to have the pads replaced and have the waste ink counter reset by a tech. Note - this is
not a chip, it's an internal counter.
Now I confess that I haven't checked that the P600 waste ink counter
can be reset, but it would have to be possible because an Epson tech needs to be able to do it, and it's been possible on all other such desktop printers without a maintenance cartridge. In fitting an external waste ink tank to the P600, such as the unfortunately named printer potty mentioned above, all you are doing is unplugging the tubing that leads from the capping station to the waste ink pads, and having the ink drain instead into the external tank. No chip involved, no lockout issues. Contrary to Gary's view, the printer will continue to work once it's fitted.
As to when to fit an external tank, my view would be that if you're going to have to do it at some stage, then you may as well do it as soon as the warranty has expired.
p.s. Just to be clear, if you fit an external waste ink tank, and eventually get to the point where you get a printer error message saying that certain printer parts (i.e. the waste ink pads) have reached the end of their useful life, then you don't need an Epson tech to reset the counter for you, you can use the WIC reset utility from 2manuals dot com. You have to buy a single use key, but it's only around ten bucks, which is much cheaper than either a service to replace the pads and reset the counter, or a new printer.