For the "hidden but not really hidden especially now" feather block (which already has a texture. You would have known if you paid attention.) there is an idea for having fall damage reduced and maybe tiers (upgrade-able)

Done adding feather block as of October 24th, 2014

The feather block itself is not a fall damage reducer but there is going to be a fall damage reducer block with tiers

Log of 9-9-2015:

I have made attempts to make the blocks reduce fall damage but so far I haven't made any progress. I will make more attempts once I know more about how to do it.