I guess this would involve using names instead of IP addresses in third-party software configuration?
Pi-hole wouldn't stop you from blocking local domains.
So more generally, your sentence becomes: Permitted domains should always be permitted.
If in the past your clients were referring to certain servers/services by IP address, but are configured to do so by name now, then Pi-hole's dashboard reflects DNS resolution requests as they happen in your network.
They still may be excessive, i.e. happening more often than they'd have to.
If a client would lack or ignore a local DNS cache (as maintained by that client machine's OS), the client may excessively request resolution.
In such a case, it would make sense to either enable a client's DNS cache or to use IP addresses instead in order to avoid unnecessary DNS requests.
But even if the client would correctly cache a DNS reply, it would do so only for the duration of its TTL. If the TTL is low, that may also prompt a client to repeat DNS requests.
In your case, I'd expect TTLs for local domains to be controlled by your FritzBox router, as you've enabled Pi-hole's Conditional Forwarding. My own FB is using a local TTL of 10 seconds, which is a sensible value.
But in case some of your Local DNS Records are held by Pi-hole, we should also check your Pi-hole's local TTL setting:
Run from your Pi-hole host machine, what's the output of:
grep -nR local-ttl /etc/dnsmasq.d*
If that comes back empty, that would imply a local TTL of zero, and you may want to consider adding it via a custom configuration file.
And last not least, if you cannot control those requests otherwise, you may filter them from appearing in the dashboard via Settings | API / Web interface.