The IP Update API is described as legacy and the REST-API should be preferred according to the docs. However, when you have to update your IP, you want short TTLs which the normal API does not allow.
I saw the offer to request shorter TTLs, but the normal API does not seem to be a full replacement with the defaults yet because short TTLs are a big point of DynDNS.
So is the IP Update API eventually not legacy?