Grome allow to make erosion, vertical cliffs :

How will it be xported to A7 ? in a simple model format i think : not optimised, caus because it's not terrain system it won't have LOD and not as fast to render it it is very complicated, it will have millions of polygons !

Caus with terrain system of A7 (it's standard terrain not voxel), you can't have verticall cliffs or erosion like Grome.

For the grass ,and trees you draw in Grome , onec again do you really think you push export button , and have trees , and graas taken accont like multi instance on terrain of same object ?
Same for multitexture ,can you do it in Grome, and not sure A7 will detect that it must apply a terrain shader and use the textures of the folder ?

Same thing for water, not sure shaders are compatible , neither sun parameters and other things.

Can't wait to have your answer on all that
But if it would work, for 200$ it would be some outstanding new way to make terrain for A7 indeed !