Is there a way to exclude certain clients from logging?

[yubiuser]

No, you can't stop logging for certain clients. You can only disable logging in general.
There is a feature request you might want to support

Option to not log selected client(s)

I'd like to have one (or more) clients not show up in the logs. They do not to be logged at all. They need not to bypass the pihole. It is great that the pihole filter applies to them, I just want their 'noise' removed from the logs. Is it possible already, or would this be a new feature?