does anyone know how to do that properly? Because in DnsDhcp only
"Minimum TTL" is available in the "SOA Information" tab. This value
certainly changes the "negative caching TTL" in the SOA, but does it
also influence $TTL?

Additionally in DnsDhcp the "negative caching TTL" is only settable in
"hours", but I want something like 10-120 seconds for our fast-changing
dynamic DHCP zone. Is there a way to do that besides editing eDir
directly? For now I have set it to "0 hours", but that wouldn't be good
if this value also influences $TTL...