The first one (ZeCannon) is really a threshold workout. Even though you're a bit above FTP, it's still right on the Z4/Z5 border. The first couple reps won't seem that hard, but the 1' rest really takes its toll on the second half of the set. If done right with an accurate FTP it's a pretty tough workout, especially if you extend it by adding more reps.
Your second option is more of a VO2Max workout, although I would say if you can do ZeCannon at 108% you should be able to do the VO2 session at higher than 110%.
As far as bang for your time, the ZeCannon session is more time-efficient just because there's a lot less rest. You can do that workout in an hour including warmup/cooldown. But again they work on different things so it depends on what you want to get out of it.
Good insight. Just purely fitness, can't have any goals without knowing when mom comes out of stroke rehab. Makes me think I should just do one TT & Vo2Max interval per week.