Godfrey
somewhat colored
I haven't noticed any lost features on LR6.14 and I am running MacOS 10.14.6.
Shawn
I can't remember all the specifics that well but one piece that dropped off the table was the Maps module: it stopped working some years back.
Remember that 10.14.6 (Mojave) is three major macOS releases back, vintage Fall 2018 released. When Mojave was updated to Catalina, that's when the SPI was updated and Adobe decided not to pursue updating it any further. Big Sur was the most recent macOS release, and it will likely be superseded yet again in September-October time frame since macOS is typically on an annual update schedule these days.
G