When printing the first 5 or 6 layers of a dual extruder model, the idle extruders are leaking slightly and leaving a "ghost" print to the left and right of the actual print. I'm not sure if this is just a functional limitation of my rig, or if there's something more I can do either in firmware or in S3D to try to mitigate the problem. In almost every other way, the prints are perfect aside from a small cooling issue when doing very fine details on top layers. I'm using both priming pillar and ooze shield, but once the head is significantly off the bed (let's say above 0.5mm) the problem reduces then disappears over the proceeding couple of layers.
I've had a search around but can't find any matching advice. I have a Prusa i3 clone (Anycubic, but with a GT2560 board running Marlin 1.1.5) to which I've added 2 bowden-fed E3D v6 clone hot ends, with 0.2mm nozzles. My print quality with single extruder models is great using either extruder in isolation - I've got my flow rate just so for both extruders, they're well calibrated and I regularly take measures of the filament diameter for each extruder. The nozzles are very carefully aligned to be the same height, and I've used a number of calibration models to get the X and Y offset as close to perfect as I can get it. I've set as generous a tool-change retraction as I can (11mm @15 mm/s) without the filament exiting the hot zone - if I go any further the cooled filament end "bulbs up" and won't go back in to the hot zone, stalling the bowden and killing the print. I clean the nozzles carefully between prints and my in-print retraction and z-hop settings are keeping the prints nice and clean with no zitting or stringing, bed adhesion is good and I'm using an aluminium bed with an inductive bed sensor, which works just as it should. I only ever print in PLA, the hotend temperatures are currently 195 degrees, but I've tried as high as 210 degrees with no issues.
Any advice would be greatly appreciated!