"Life hacks" is certainly kiki, though there are many life hacks which are bouba (meditation, patience, prayer, kindness, gratitude...)
Reminded of the romantic / classic distinction made in "Zen and the Art of Motorcycle Maintenance".
Fun to think about questions like: what is the most bouba thing about Wall Street?
Or what is the most kiki thing about sleep?
The latter type of question seems to be easier; being analytic runs deep.
Your kiki/bouba classification drive is very kiki. You may end up with widely acknowledged & shared definitions...
kiki: a quality of seeming rational, with reductive pieces subject to analysis
bouba: a quality of seeming amorphous & bloblike, with difficult-to-identify pieces