DNS CAA proper internal configuration

What is a valid configuration of internal CAA records (internal - not visible in Internet) on Windows DNS servers:

• You should point to valid source of certificates - "issue" prefix for DNS record, for example if Your internal PKI is from pki.internal.contoso.com you should place record issueinternal.contoso.com or issuecontoso.com; this will cover also wildcard certificates;
• If You don't want to allow wildcards You should place another DNS record with empty source record like "issuewild;" - allowed entries is empty; 
• binary representation  of DNS record contains first byte equal zero (the higest bit has critical meaning, rest is not used now), next byte value 5, rest of record is a string data, e.g. "<00><05>issuewild;"
• binary representation must be located in DNS record of Type257

default ttl dns records on Windows

The 20 minute TTL is default with self update

The default of 20 minutes - set by DWORD named DefaultRegistrationTTL in HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters (the value should be in seconds). A reboot or ipconfig /registerdns.