Minecraft: 1.12
Forge: 2405
RFTools: 6.10 beta 4

Support block (that are not an illusion) destroys Grass paths.

Well yes... There is not much that I can do about that I'm afraid

Maybe not placing the block just under a grass path?
I'm sure you already do that for culture, because if your support blocks are on, cultures like sugar canes or cactus will not grow.

culture?

Question: what do you mean by 'culture'?

Culture is Agriculture. Sorry, I'm a french speaker and sometime I write french words.
Potatoes, wheats, and so on, in progress of growing, or ready to collect. xD

this might be able to be fixed