@Sam7919 you can pull upwards as hard as you want and they won’t unclip (unless you get the cleats designed to do so). They do tend to be a bit easier to twist and unclip, which can be a downside for rapid mounting/dismounting.
I’d say it very much depends on the type of walking. A brisk walk on uneven ground with plenty of elevation change (and possibly a backpack and hiking poles) is an entirely different thing than strolling through the shopping mall.