First, I finally published my mod on the Nexus:
https://www.nexusmods.com/witcher3/mods/2751/?
I originally wanted to improve upon it, but really haven't had any time for modding this last couple of months.
About your comment on smoke further away looking different: actually I removed the lower quality LODs entirely and only left LOD0 (highest quality) and at the same time increased the drawing distance of that. So, there should be no change from a distance, except if maximum distance is reached and the smoke doesn't render at all any more.
You are correct though, that there are more smoke particle files that I did not modify and which theoretically might be used by (a small number of) chimneys for displaying smoke from an even greater distance.
I obviously didn't check all the chimneys in the game, so those might have slipped past me. Could you maybe provide some screenshots? If I can improve that, I might do so some time in the future
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