I was never particularly impressed by smoke when I had only seen it in movie clips.
But after I had equipped a couple of my steamers and seen it live, I was sold on its authentic effect.
But are there any drawbacks. E.g. does the settled residue muck up layout surfaces after long-term use, and does the residue and eventual spillages of fluid have a deleterious effect on loco paint finishes, particularly weathered ones?

Possibly it is a patented technology and Marklin does not have access to it through a licence agreement?

Would you not use the smoke/steam fluid that is specified for the smoke generator that is installed? If its a Seuthe, use thier fluid. ESU generator, use theirs (they say their fluid is tuned for how their generators work).

The smoke does vaporise the fluid, and it will eventually settle down on things. But I've got no idea how it impacts the long term layout - hoping steamer users with a lot of experience chime in. I just ran a steamer for the first time with smoke, around my living room Carpet Bahn this past Christmas. I'm picking up my one other steamer from Rocco early next year - and it will only run on special occasions as its a museum loco on my electric era layout, so I won't get heavy use.

The fluid should not harm the paints of the locos, since spilling some on the loco and layout is an almost unavoidable thing when filling the smoke unites on the locos with the bottle and/or pipettes. But again, my experience is limited to a week or two of usage.

I'm looking forward to the piezo electric atomizer that uses distilled water in the Tiger ludmilla coming out to do its mimic of diesel exhaust, but thats not the same density of the oilier smoke fluids.