At least with Meredith, apparently not since an Awakened Magician goes past being a "human". This does remind me of another webtoon where it stars a magical guy, who had a to freeze his magical appearance at a very young age in order to fool everyone, in his world, that he is a girl. So, every time he transforms into a "magical girl/witch", he becomes a child again. In fact, I think he and Meredith would easily become very best friends if they ever knew each other. :0 The only troubling thing is that, that guy, pre-character development, was very anti-closeness to others. :/
So yeah, whenever Meredith goes into his Awakening state, he'll revert to a child version of himself. He's like the anti-Rood. Unlike Rood, whose Awakened appearance is pretty much similar to his former DK appearance, Meredith's Awakened child-like appearance is a big question mark. (Since I don't go by that other theory, unless, proven otherwise.) Poor Meredith. ^__^ It seems he doesn't look like that big of a deal unless he turns into a kid. And yeah, the Tower people will definitely not recognize Meredith in his real form since he lived that long.
As for Rood, we can blame his uncle and auntie for starving the poor kid. That affected his growth spurt. I'm kind of fine with Rood being this way. He's like the type, who clearly can't be read/judged by the cover. Meredith is also someone, who is in a similar boat just for height difference. Makes it fun. (But now, we know how tall you are, Ghoul-chan? :D Awww...)
^___^ Take as long as you want/need on typing these summaries out.