
As an example LED bike lights were illegal (despite being fantastic in terms of efficiency, longevity, added safety from increased visibility) but were only made legal in 2005 almost 10 years after they became widely used & sold here in the UK ..for many years I could have been cautioned or fined by the police, a bit like e-scooters are illegal (in the uk) now.
"In many countries, LED flashers are the norm for rear lights. In others such as Germany and the Netherlands flashing lights are forbidden by law. In the UK flashing LEDs (front and rear) are legal from October 2005, provided that the lights conform to the requirements of the current Road Vehicles Lighting regulations.[14] Many vendors claim EU compliance, however, this provides no consistent safety or legal value across the Union"
So in terms of battery storage many countries will need up to date "help" in order to accelerate sales of battery product, because too few people understand the differences in Li- battery technology & its risks OR added safety.
So when the rules come in they will be likely wrong, & outdated, ..until then we have to guess & build around so that safety inspectors & insurance companies are ok with it.
Part of the recent "worry" is from cheap, non reputable e-scooter fires, (so build quality, waterproofing & battery chemistry are important to be made legal eventually) ..something which hasn't necessarily got back to all manufacturers in china & elsewhere.
A scooter was on the london underground & caught fire, a few days later numbers of public transport battery incidents were publicised & a general transport ban happened.

For instance waterproofing is essential for the uk ebike & e-scooter market, but there is really only one brand doing that with certainty.