I recently installed a genuine e3d volcano hotend on my ender 3 w/ skr mini 1.2, EZR struder, a bowden tube and a 0.6mm nozzle X. I have it mounted with the hero me gen3 duct and a nice 4020 fan blowing over the hotend. However... despite all this, I haven't been able to get a single print done without a jam. I have tried already: 1. Adjusting retraction settings; even at 2mm 45mm/s, I get jams (and a lot of stringing before that). 2. Reapplying thermal compound on the heat break (heatsink side only) 3. Reassembling and hot-tightening the nozzle (many times). 4. Trying the stock 4010 fan, thinking maybe I had too much cooling? No dice. 5. Using higher and lower temps for PLA -- around 210 is the highest I can go without too much ooze. 6. Replacing my PTFE tube and ensuring it sits flat against the heat break Current on my extruder stepper seems fine and the ezr struder is more than capable, and I've even switched to spreadcycle. The first few layers seem to go down fine, but some time after that, the extruder starts skipping steps because there's too much pressure. When I cancel the print and keep the nozzle up to temp, I can feel the blockage clear as I push it through by hand (with quite a bit of force) and if I disassemble it first instead, there is indeed a solid chunk of plastic caught in the heat break. I haven't had any problems at all with the creality hotend, so this is really frustrating. I feel like it must be heat creep, but I don't know what more I can do. The hero me fan duct seems more than capable... is there anything else I can try? I still am playing with acceleration and retraction distance/speed... but not optimistic. I'm not chasing speed, just trying to get a successful print. Any suggestions what else I can try?