As I said on another forum, this is interesting but not enough. It doesn't explain much about AI or the best ways of using it, a couple of which have already been mentioned in posts to this thread.
The best thing about AI Fingered mode is that it's totally 'transparent' to normal chords, regardless of the inversion that they are played in. So my strong recommendation is that everyone who does not need '1 finger chords' in MultiFinger mode should go straight to AI Fingered. AI only starts to work when you ask it to, when not needed you won't even know it's selected!
If makes short work of things like C/G or G/F. It's capable of doing chords like F/G, though the display will be a little confused saying F*/G. Rootless 9ths and 13ths are easy, following exactly the chords that the organist would have used (remember that arranger keyboards are the children of the home organ) along with a foot on a pedal note. The more you ask AI to do, and the more you understand its logic, the more it surprises you.
Steven Sondheim's harmonies are often complex, how about an opening sequence of F 6,9 alternating with Cm9/F? AI can do that, albeit with a 5 note chord (in theory you can use 4 but I haven't got a keyboard here to try it) and a chord where the thumb has to reach over the second finger to play it more comfortably.
Some time ago, Jackie Marsden wrote a couple of articles in the Yamaha Club Magazine which were very, very good, but even they didn't cover all of what was possible. I've been asked a few times to rewrite and extend those articles and, given enough time and a bit of assistance, it's something that I will get around to. Writing what will be a few thousand words is time-consuming! And I'd need Jackie Marsden's blessing to do so.
One little tip. If you have a 61 key instrument, then set the Style and Left key split to G2 rather than F#2. This will allow for the G/B chord that is common in the key of C. Practically every chord you'll ever want can be played with the key split set this way, though at Grade 8 and Diploma exam levels, my students have come across very unusual, but workable, AI chords that have required a key split as high as Bb2!
One little snippet. Not so long ago a good friend of mine (who's been in the business as long as me - 48 years!) told me that AI was actually 'invented', or devised, by his late father, also a friend. He took it to Yamaha and they snapped it up. I'm glad they did!