Most people already use child proof caps don't they?
Only time I've not seen them was when ordering large bottles, like 120 or 240 ml, which had separate caps.
Personally though, the bottles I use for my personal DIY liquid dosn't have child proof caps. Before starting DIY, I had also bought some empty bottles without child proof caps so I could swap the bottle or cap when I bought eliquid.
On a side note, that 2nd statement kinda makes the law pointless.
There is no law preventing somebody from going to amazon or some other place and just buying regular dropper bottles and swapping the liquid. Thus eliminating any 'child safety' reasoning behind the law. At least it will help protect the seller from being sued though.