Just a couple of swaps I'd had on my mind.

Blue
Deeproot Pilgrimage signals the tap/untap theme well and at a decent rate with a good keyword. It takes minimal enablement to start going building out a board of tokens if you're able to control the opponent.
Robe of the Archmagi always reads really cool, but when comparing it to Eagle Vision, which offers a similar payoff for a similar hoop, its weaknesses become very clear.

Red
Breeches was a card I had considered during early drafts of the cube but had cut it as potentially too strong, which shows just how desperate I was to cut cards from the pool at the time lol.
Hellspur Brute has been on the chopping block for a while. It's lasted this long for a reason, it's more or less the best version of this style of card, I think. But that type of card doesn't seem to stack up well in this environment.

Multicolor
Those who have followed this cube may notice that the Alania/Sarkhan swap is a direct reversal of the last time I updated this slot. Nobody wants to give their opponent cards on this kind of scale. It's much better as a political tool for commander games, so Alania may come back for the commander module.
Sarkhan remains an odd duck. He doesn't work with ETBs, which are a big part of blue's creature suite, but there are a good amount of red cards that work with him. And there are some specific cards that he can act as a pretty powerful force multiplier for, the tricky part being that those cards are already strong and worth playing without Sarkhan.
I had considered the newly printed Fearless Swashbuckler for this slot, but I think I would want at least two or three more vehicles for that. (The vehicles have haste ability actually does the card a disservice, as it feels like tribal text, which is a red flag for inclusion here.)

Colorless
Fell Flagship didn't feel like it was asking too much before, and that might still be the case, but Dollhouse of Horrors is just such a nothingburger of a card, Doing way too little for its cost. (This swap was motivated by the previously mentioned Swashbuckler, so it may contribute to that card coming in at some point.)