Is lying about simple matters—for the purpose of admiration—considered an egregious lie that necessitates ending an engagement to a righteous man?

The suitor is a stranger to his fiancée until the marriage contract is concluded, so correspondence with him is not permissible except out of necessity and with the assurance of no fitna (temptation/strife). If you are certain of his lies, then lying is a dispraised and forbidden characteristic, except in what the Sharia has permitted: reconciling people, a man's statement in war, and a man's conversation with his wife and a woman's with her husband. If the suitor's righteousness is predominant and lying is not a general habit for him, then this does not necessitate rejecting him; rather, he should be advised to avoid lying and to be truthful.