My 18 month old DC has now demonstrated that they can escape from reins, strollers and 5-point harnesses. Any advice on how to keep a very determined child securely in their pram or car seat? They can press the release button surprisingly firmly, and put a lot of concentration and effort into wriggling out of things (plus a bit of hypermobility seems to help them with this)...
I think superglue might be frowned upon...
Distraction with books or interesting surroundings can work for as long as they stay interested, but doesn't physically prevent escape...