It is all good as far as it goes, and if more MPs sign all the better but it will achieve nothing much in the short term.
An early day motion is a chance for MPs to express opinions and put them on the record, they rarely lead to anything concrete.
It is good in that it helps counter the negative press that vaping and that is good, but it will not lead to any significant change. In the longer term it is positive and may help reduce the chance of further regulation or taxation.
The House of Lords debate this evening is the same, it is a chance for politicians to express opinions and we could do with more positive opinions but there is no obvious path towards positive change from these expressions of support for vaping.