Hi,
this mod might end up in some modpacks and people either like or hate it.
I would suggest to add an enchant for boots to make the leave blocks walkable again. (and/or a recipe for said enchant, so that its obtainable early game)

Please give an occasion that you need this feature

shearing leaves from top to bottom...

exploring with jumpboost or jetpack and jumping from tree to tree...

i wouldn't ask if the non solid stuff wouldn't annoy me while playing a 3rd party modpack