[thaumasiotes]

> I often ... write "though" when it should be "although"

That is a purely imaginary "error". Anywhere you can use 'although', you are free to use 'though' instead.

[bjourne]

Yeah, but you cannot use although anywhere you can use though, though.

[thaumasiotes]

That's true, but the one-way substitutability still means there is no such thing as "writ[ing] 'though' when it should be 'although'".