JPOG Jungle Mod is a mod made of edits to several tree models, with many having extra ferns and smaller trees next to them as well as size changes making certain trees larger. It makes the modern tree foliage much more dense. There is much more size diversity among the plants, giving a more complete jungle feel. This mod only changes models not textures, so it should be compatible with most mods. My foliage in the photos use JPOG Forgotten textures. This mod does not change the bubble values of the trees at all, so if you want to up the density further that is still an option for you in your own game.
The Jungle Mod for your JPOG. Extract the file and place all of its contents into the Models folder
Credit to Equinox for his modding tool which allowed the model editing of these trees. This mod has great density with vanilla settings, but you can further increase that by editing the Bubbles values in the TreeDist file.