.DE is particularly hard because they lock down the zone file. GTLDs like .INFO are easier to get because the zone files are open. We have 9 years daily granularity for the gTLDs.
Would love to clean up the U/X so it's clear what we have data for and what we don't to be completely transparent.
Thanks for the note.
For example, WHOIS info https://i.imgur.com/WNpyvcl.png should maybe show something like "none available", or "no WHOIS info is available for .de", or "go to denic.de to see WHOIS info" (DENIC offers the WHOIS info, if you enter the captcha). On the other hand, http://whois.domaintools.com/kuschku.de (a competitor) correctly shows the WHOIS.
Second, with the domain – I have no idea how the wrong value ended up on there.
The UI enhancements you mention are excellent - we will implement this shortly (not only for .de but for any case where we can not output any values).
Feel free to contact us at the e-mail address given at the bottom on every dnstrails page!
kuschku.de has, for the past 2 years, always pointed at 51.15.1.223 or 163.172.217.134, never at 204.236.227.242. Funnily, for other domains pointed at the same IPs, it has correct data – e.g. quasseldroid.info correctly shows the IP history.
The datasets used here seem of questionable quality, souring the taste of this awesome feature.