Let's be clear, by backroutes I mean solutions that are _easier_ than the intended solution.
Well okay I see where you're going, but I can also see endless debate on what "easier" really means.
For example, is the ceiling backroute to "Stepping Stones" really any easier than the intended? The intended method certainly is more obvious to conceive of since the terrain layout and title screams for it, and isn't too particularly difficult to execute since if I recall correctly, you have diggers for cutting short your building so they can align with the stepping stones.
Things can get murky since there's both the aspect of how difficult it is to conceive of a solution and how difficult it is to execute the solution, even ignoring the inherent subjectiveness in both.
And what about "We All Fall Down"? Unless by "backroute" you mean the one from WinLemm (and ONLY WinLemm as far as I know) where they stupidly increased the game's max safe-fall distance. Otherwise the only backroute I know of involves using fewer diggers, which to me is hardly the most obvious solution either to conceive of or to execute.
I guess it's still fair game though to remake levels with more difficult backroutes (whatever that may mean). Instead of releasing multiple versions involving the more difficult backroutes, just release one remade version of the level that enforces the easy intended solution, if possible.