I think that is a problem in photogrammetry. I whinged about that too because I like swanning around at tree top height around my locality. I bought Accusim Seasons which lets you reduce tree height but not with photogrammetry turned on. My other sim was Aerofly FS2, and they had trees in roads, buildings etc. But .... you could change tree density right down to zero. Be nice if we could do that in MSFS.