Per the last, the TPA Malto and Ethyl Malto are the same, however Maltol and Ethyl Maltol are different compounds that have some of the same traits.
Maltol - Wikipedia
Ethyl maltol - Wikipedia
Although they are both sweet in aroma, ethyl maltol is more desirable for the purpose of sweetening e-
juice *as it has a better aroma and lower boiling point.
Due to the nature of the manufacturing process preparations of one compound are likely to contain some amount of the other.
(*edit clarification)