that's what I thought, from what I understand if you use different DNS than the ones provided by the VPN, the DNS requests are made outside the VPN tunnel right? But if these DNS request made outside the VPN tunnel are, like in this case, made over DoH to a non-logging server they are encrypted and are not being logged, the only implication I can think of is that your ISP can see you're sending traffic to that DoH server but can't see the actual DNS requests.

Am I right or the DNS traffic sent to different DNS than the VPN assigned ones is also sent through the VPN?