choosing the pinkest, fluffiest unicorn of them all

Bercow's down selection from 16 to 8 isn't so different from my prior guesses.

I'll use my original prediction percentages again, with a couple of adjustments for the smaller set. Labour has whipped 3 of the votes, too, which defeats one of the objectives of a free vote from Parliament.

1. There's flavours of Customs Union (81%), EEA/EFTA (69%), Common Market 2.0 (61%), and the Labour Plan (47%), which are all variations of the same continuum, but has tactical voting from Labour, to skew the outcome. Some of these are also linked to the Political Declaration, which is post Withdrawal Agreement.
2. The first set of options play against No Deal (64%) and Revoke Article 50 (I up its chances to a still lowish 42% in this new line-up). The big loss is removal of Revocation to replace No Deal, which could have changed the outcome. Without it, there's really very little change to the overall picture.
3. Then there is a confirmatory public vote (24%). In other words No Second Referendum.

At this rate the first round of votes won't really do anything, but the subsequent time-line based down selection might.

By my reckoning, if the chicanery continues, its chances of winning are actually increasing.