I was having lots of problems with filament jamming after around 30 mins on all my prints.
I fitted a Phaetus dragonfly BMO hot end and a 4020 fan to stop heat creep.
Without any other mods to the firmware/cura settings the print quality has improved massively.
Well worth doing in my opinion.

Hello @Robin Benford Would you please take a picture of your build.
no just the single hot end. The 40X40X20 fan def blows more air around but its also a fair bit noisier. Ive not even started on sorting out the DSH yet, until Ive got the single hot end running properly.
How did you fit the new 40mm fan on the heat-sink? Do you have a custom mount? I'm looking to upgrade the fans for noise control and better cooling. I ran into a kind of heat-creep issue, which was solved in my case by readjusting the bowden tube to make sure there was no gab before the heat-break.