Adjective usage of 'mystic' vs 'mystical'

The SOED does not take those two adjectives as synonyms.

(SOED) mystic
4. Of hidden meaning or nature; enigmatic, mysterious.
5. Inspiring an awed sense of mystery.

(SOED) mystical
4. Of or pertaining to mysterious or occult rites and practices.

From the above ngram it appears that among persons wrapped in mystery there are many more reckoned to be so as relates to their practices or the rites they perform, and are thus spoken of a being mystical. On the contrary, a mystic person will inspire a sense of mystery through the bias of mere appearance, language, thinking.

You could make the same points about "magic" and "magical" (Disneyworld includes the "Magic Kingdom," but until recently it featured an airport shuttle bus called "Disney's Magical Express") and many other adjectives ending in "-ic": mythic/mythical, poetic/poetical. The thread Why is it "geometric" but "theoretical"? shows that it's a case of parallel evolution. As it notes there, some usages have "settled" into certain connotations (with "poetic/poetical", I'd say that "poetic" means "having the qualities that poetry has," while "poetical" means "having to do with poetry").

I'm out of my etymological depth, but I feel like "-ic" endings are more preferred today and "-ical" endings are more archaic, so on those grounds "mystical" might carry more aura of the arcane (while "mystic" might suggest... pizza?).