I'm not from IJM, but I will make a few observations. One is that sometimes you have to wait a day or two for an answer on this forum, but in my experience all questions get answered. They are quite generous with their time in doing so. If your need is urgent, contact them direct.
I can't comment on the ink drips. I have had this problem with older cartridge designs, but not recent ones. Didn't have this issue on my 1410 when I had it. Based on my experiences I'd ask if these carts were from IJM and whether you followed the filling instructions.
But my main point is that you should not expect to be able to just slot in one or two ConeColor carts in this printer and get the exact same colours. This printer is a six colour printer that takes Claria dye inks. The ConeColor inks are pigment inks intended for the 7/8/9 ink pigment printers. They're not going to be an exact colour match. They can't be. And it says so on the IJM web site:
"The only thing it is missing is archival inks. So we stepped up to the plate with a refillable cartridge system running our ConeColor K3 deep color gamut pigment inks. You will need color management. You can either provide your own with a device like the ColorMunki or download our free library of professionally made ICC profiles from the ConeColor website by clicking here."
What this means is that to get an exact colour match you will need to either use one of their custom colour profiles or create your own or get IJM or someone else to make you one. You'll need to print from a colour-managed application like Photoshop, and turn off colour management in the printer driver.
Actually it's a little more complex than that. As I understand it you've only replaced one colour and the other five are still the Epson ones, right? They won't have a colour profile for that combination, and personally I wouldn't pay for one myself if I intended to replace more Epson Carts with Cone Colour ones as they ran empty - you'll need a new profile each time you switch one more cart from Epson to ConeColor. To make this to work you need to swap all carts to the Conecolor [edited] ones and get a new colour profile for this inkset and your paper on that printer.
You can test whether I'm right - that the problem is one of colour management rather than a missing colour channel - by doing a simple nozzle check. That will show if all channels are there. If they are then the issue is you need a custom colour profile and colour management.
You're not going to want to hear this I guess. You either have to commit to the ConeColor system fully, or go back to Epson Claria.