Difference between Epson WF-7710,7720 and the 7820,7840?

[Snorunt93 0]

So for a few years ive been using the WF-7710 and WF-7720 (identical to the 7710 just with a 2nd paper holder). As you probably know, with these printers, they can be made chipless but can also use CISS systems and refillable cartridges with a chip resetter. 

Now i eventually was considering getting a newer version, with those discontinued, the newest options were 7820 and 7840. My question is, did Epson change the firmware or something to make them incompatible for people who want refillable cartridges? And will these models ever get a solution to solve this? 

Id also say that i also have a WF- 7210, which is very similar to the 7710 in that i can use refillable cartridges etc. but the newest version of that is the 7310. It seems that might also have updated firmware thats unable to use refillable options. Are all new Epson models like this? Is there any current models that can be made chipless or use refillable cartridges? If so id like to know which models. 

[John_Admin 389]

7310, 7820, 7840 are not in our development scheduler at this moment