Ruble seems a problematic topic for many,
but I think it could be done in a way that would keep everyone happy with adding to the game mechanic.
1)designating it to be cleaned is BAD, rather it should be designated automaticaly if there exists a valid stockpille
1.1)not cleaning it up (via not having a proper stockpille set up) should slow down the movement of dwarves, but not 100%obstruct it, as that would in a way be stupid since dwarves would mine themselves in and couldnt get out
2)there should be a special stockpile for ruble, since that would basicaly be gravel, it only makes sense to pile it up high
3)the question about ruble is really 'how could we use it?' gravel roads, gravel walls?, cement?, landfill
3.1) landfill: i propose a new designation job, an order that when issued would make dwarves haul gravel from its stockpille to the designated area and chuck it in untill its full, (an opposite of 'channel'). Such a tile should as such again be treated as a normal full tile my the game (which in theory should be minable again)
3.2) advanced use of landfill: filling up aquifers?
a totaly off thought: it would be great if dwarves could carry dirt(earth) in buckets or wheelbarells, to designated tiles, which would enable growing forests or farms on constructed floors (maybe just carry mud?)
anyways thats my 2 cents