Sorry to likely rehash an oft debated topic, but if anyone could direct me to past posts on this subject and/or offer more insight as to situations in which this method is more conducive to performing work (i.e., more economical, effective, efficient), I'd be thankful. I haven't yet tried it, but the more consistent (?) power delivery sounds appealing, even for road. also, is 90 deg. OOP the only desirable position? how about 180? too twisty?

Might this setup allow a "smoother" spinner to assist a compatriot in developing a smooth spin, or would phase synchronous cranks actually help more, or would possibly neither help?

Howdy from Tucson!

We have been pedaling OOP for over 200,000 miles (that's the correct amount of zeros) in 30+ years of tandeming.
For us 90 degrees OOP works best although any amount of OOP is do-able all the way to 180 degrees.
There is also left and right footed OOP (with either left or right pilot foot leading).
Experiment around a bit and see which feels more natural/better to your team.
Advantages to us @ 90 degrees OOP: always a power stroke going over the top; less flexing of frame; easier startups + quicker get-aways at lights. Stoker stays seated/clipped in at all stops. Easier climbing.
Disadvantages: You 'could' clip a pedal laying a sharp corner; more difficult (but not impossible) for both riders to stand comfortably. . . and some folks say: "it doesn't look nice."
We ride road only; seems off-road you'd have to be more conscious of pedal positioning to avoid obstacles.
Give OOP a try for a few weeks and then decide what you want to do.

Pedal in TWOgether!
Rudy and Kay/Zonatandem