Modo will open .lws scenes, but Terragen is exporting LW5.x scenes..
Manually text editing them loads them fine, or re-save in LW, load in Modo.
These days lightwave scene files use LWSC3, Terragen is using LWSC1.
I'm not sure why Terragen breaks the .lws into multiple objects (Oshayan?)
In Terragen 0.9, LW6.x has a point limitation of 257x257 (which sucks)
But this limit was removed, long a go with the .lwo format.
I'm not sure if Matt's aware of .LWO's updated spec format.
So i don't think it should need to break them into multiples anymore,
but it still works fine, it seems to export great detail in TG2.