Research (LW2)
Research in LW2 proceeds much the same way as in vanilla XCOM 2, but is expanded.
Tech Tree
A tech tree, which is up to date as of Version 1.1, is available here
Another tech tree made by exodusinfinite for LW 1.1: (A comprehensive version including item stats is available Media:LW 1.1 Tech Tree Comprehensive.jpg)