News to me!
TAF's feel really good to me too. It incorporates a different flipper with each shot (well I guess you could backhand the ramp) and different positions on the flipper with each shot. Dr. Who falls short for me personally because it feels like they're all tip shots. It's not a bad combo, just not better than either of TAF's 3-ways.
And yes, Shadow 7-way is probably one of the hardest to achieve. I did a 6 once, which was all 4 ramps then left orbit-center loop. Working in that extra right orbit shot is definitely not trivial... Your best bet is probably to start with the right orbit then loop passing and doing the other 6. Otherwise at some point you're flailing the right orbit up the right ramp, and good luck with that.
That's stringing shots together, not really a set sequence. Even though it's similar, it just not quite the same. I prefer the set sequence, even though I have written rules like AFM's (WPT and LOTR).
True story: at one point in time I was going to add a rule to LOTR that started by making the Shire (mystery) target into the VUK called Gimli's Challenge. It was going to give you one shot, and if you made it, light another, etc. up to a 6-way combo, which if you completed, lit extra ball. There's probably even dot support for the rule, but I just never got around to it; the game didn't really feel like it needed it.