While a bit off-topic in this thread, still a quick/brief response, as it seems there might be some misconceptions here.
Ok, understand the formal/legal point, even if mostly irrelevant from technical point of view, or even counterproductive.
Depending on circumstances, this may actually be rendered more difficult by everyone syncing to PTB’s timeservers.
Again, this may be less accurate when syncing to PTB timeservers than otherwise technically possible.
As above.
NTP and UTC have nothing to do with daylight saving time whatsoever, or with local time, e.g., “german time”, regardless of whether provided by PTB or any other source. It is a matter entirely local to each individual system to “translate” UTC/NTP time to the local time/time zone for presentation, including considerations regarding DST.