If you're looking for an "
all windows are entrances" mod, there aren't any that I know of. It's a lot of effort to add all those pairs of teleport markers, plus the activators for them, and link them all up. Plus you'd never keep up with all the new windows other mods add to the world.
A few mods use specific windows as entrances. You can make anything a teleport door if you need to, and there have been a number of interesting ones in mods recently.