After I finish the 3x16 at 100% FTP I’ll decide about the 4x16 at 102% - I kind of want to give it a try just to see. If I feel ok after the prior workout I’ll probably give it a try
To be fair - a 20 minute test number would be something like 105.5%, not 102%. So they aren’t quite asking that you do 4*(20 minute test number).
I tend to think the 4x16 at 102% is possible, although possibly only with an easy run-in, and not in the fourth or fifth week of a training plan. I don’t think the 4x16 at 104% is likely to be possible regardless of preparation, but who knows.
My overall feeling on this iteration of the Polarized plans is that they start too easy and finish too hard