The manual page on the Layout Engine points to the official Yoga documentation page and says the mapping of properties is almost 1-to-1 with UIElements’ properties. While playing around with UIElements I noticed the align options offered in Unity are a subset of Yoga’s and I rather like the baseline option Yoga has.
Are there any plans to implement all the options available in Yoga in UIElements?
It’s always been our intent to increase CSS parity, in general. As for align options specifically, these are not our highest priority at the moment (among other CSS parity tasks). Were you looking for something specific that is missing?