However, after many years of EOLs to grass by UK Mil training (and that is many thousands of EOLs) and only one (to my knowledge) problem caused by the surface, I think the grass is a pretty good option - maybe you just have the wrong sort of grass in the US
Crab, as a Brit living and traveling between both countries one of the first things I couldn’t get my head around was the grass in the US, you have Bermuda grass, zoysia and fescue. I’m sure some varieties are probably more suitable than others for a helicopter landing! As opposed to what we have in the UK called grass.