[Opinions] I agree - and spell it True
I agree that it sounds better as a middle name (kind of like Rue, another one you could use instead). Also, that way if they don't like it, they don't have to use it and vice versa!
I definitely think it's better spelled True. Tru looks like a brand name. I personally really dislike it when people change the spelling of word/place names to make them more (I'm guessing) name-like or name-worthy. If you want to name your kid London or Rain, I say name them London or Rain, not Londynn or Londin, Rayne or Raein or something (sorry Rainn Wilson! I actually think your name looks kinda cool - see, even I break my own rules! haha). But in general, everyone knows where the name came from, and it doesn't make it more of a "Name" to change the spelling, rather the opposite.
Sorry, I rant!