I used Aeroshell 560 from the late 1990's on, in both my 206s and my BK: third generation low coking and met the specs for the JetRangers. Coking issues on the LTS101 led me to that choice with expert advice, it improved the oil galleries in the LTS 101s and was far cleaner at oil changes in the 206s than Jet II ever was.
The 'puff' of smoke in one of the photos is far more than a puff, IMO, and is white not black. Agree that is could be indicative of something more serious.