The remainder are user preference
"We feel like just the two of us present," Daniel says
A 2014 report on a conference of the parties to the WHO Framework Convention on Tobacco Control "invites Parties to consider prohibiting or regulating [ENDS], including as tobacco products, medicinal products, consumer products, or other categories, as appropriate, taking into account a high level of protection for human health." Much depends on what is considered "appropriate," of course, but is hard to come up with a public health justification for laws that allow the sale of combustible cigarettes while banning the sale of a much less hazardous alternative.
How to effectively clean the filter, first clear the small hole of the filter, slowly pull the lever to prevent tar from splashing onto the body, and then wipe the filtered tar with a tissue
While I didnt find great data for LMICs, the Global Tobacco Surveillance System (GTSS) has limited data from some countries on self-reported plans to quit (maps below, sourced from here)