When I last tried deSEC, the service was reliable and well worth the price of admission, but the web UI and API were both quite rough, and propagation tended to be quite slow. It was annoying to do an ACME DNS01 challenge on it, for example. IIRC, the API didn't have a complete set of replace/edit endpoints, so even DNSControl (https://github.com/DNSControl/dnscontrol) would leave records nonexistent for a while while during updates.

As an aside (though this certainly applies to deSEC) it's strange to me how so many DNS services (free or paid) struggle to import simple Bind zone files, often either giving a vague error ("one or more records could not be imported"), mangling records, or even just silently omitting records. Parsing a zone file has some gotchas, but it doesn't seem like it should be that hard.