The only numbers I will ever spell are one and zero, and only when using them as a pronoun, or for emphasis, respectively.
Is there ever a reason to not to use symbols when dealing with numbers? Why would "fourteen whatevers" ever be preferable to "14 whatevers". It's just so much easier to read numbers as symbols, not spelled out.
(Caveat, not including multipliers, like "273 billion").
Remove ambiguity at all costs!
But if they insist I write things out:
Ten-one Ten-two Ten-three Ten-four
I don't think it is clear as 11, 12, 13, 14 but hey who am I to argue?
You're in an engineering community, is ten-one actually wrong?
Consider the sequence: One, eleven, twenty-one, thirty-one, fourty-one, fifty-one... One hundred and one.
As far as the convention of writing numbers out in words when they're less than 10, there's also conventions for less than 15, wikimedia uses the convention if it can be written in two words it's optional to write it out as words.
Just a small note on this, style guides have all sorts of weird rules about spelling out numbers, most of which I personally think are nonsense, hence making a meme. Not necessarily just less than 10