Looks interesting! What are the advantages (besides the mentioned ones) and what are the disadvantages?
The main disadvantage is that due to the UI/UX of domain control panels, managing anything more than a few paragraphs of text gets messy really quickly. But that could be actually an advantage, as the DNS is not particularly well suited to serve large amounts of data, and the app itself is meant for small and simple websites.
So you are relying upon the server that is caching those results to serve your data. The intent of DNS TXT records was not to provide you with a content distribution network for free.