This is to confirm that thus far, when the chips have been disabled, the following behavior will occur when reset.
The chips will report FULL when reset.
As the ink is consumed, the FULL level will be sticky and remain there for a long time and the ink level monitor will be inaccurate as far as the intermediate levels are concerned.
When the ink levels get CLOSE to being low, the ink level display will show about 80% full.
Further use will use the ink AND the printer will report a LOW condition when the optical sensor kicks in and detects that the reservoir side has no more ink.
There is broad consensus that at this point, we should reset the cartridge chip and refill it and we should perform this on ALL the others at the same time to extend waste ink pad absorber life. Doing so, will pretty much make the ink absorber pad life a non issue for the life of the printer during normal use.
So the critical optical sensor, still works and will report when the tank side is empty even after the chip has been DIMed and RESET. This fulfills the KEY role of a working chip on the printer to allow the critical optical sensor function and its warning.
In the new year, we will see whether Redsetter will be able to determine what "routine" Canon has thrown into the works to cause the non display of intermediate levels and whether this can be fixed by a resetter or whether the chip has been permanently modded by Canon.
In the meantime, we can rest easy that with Roy's insightful observation and concern, further tests show that the optical sensor will warn of a low condition and we should refill at that point.
With each new generation of printers we discover something new and hopefully we find ways around it or understand what the issue is what it means.