>>davidb+(OP)
The "Texture Healing" feature is a really smart use of OpenType features to make problematic monospace combinations look much better without breaking the grid at all.
One naive way to do this would be to create ligature pairs for difficult pairs (mi, lm, etc). But instead, they seem to be selecting character alternates that fill the fixed width differently based on their surroundings.
>>turnso+B7
It really is super clever! And the crazy part is that it's been possible for a super long time, just nobody thought of the technique. Mad props to Riley Cran and the entire crew at https://lettermatic.com for devising this technique as a part of this project.