an airline using some kind of netting restraint
I know some of Jet2's 733's have these, but that will be a relic of the previous owner (I think they have a few ex-Ansett, Lufthansa and some US derived airframes). Its just a shallow (4 or 5 inches), stretchy net which effectively extends the bottom edge of the locker upwards and is in position all the time, seems a sensible idea to me...
What is perhaps more worrying with BA's new weight limit is the likelihood of overloading the locker structure, which under more extreme loading could well break free...