impact of qname minimization with Unbound as forwarder

[Sohka]

Hi,

I would like to configure Unbound as a DNS forwarder with Quad9 as the
upstream recursive resolver.

I read in their best practices document that the qname-minimization
option should be disabled as it significantly reduces performance.
https://docs.quad9.net/Quad9_For_Organizations/DNS_Forwarder_Best_Practices/#__tabbed_3_3

Is this correct? I thought that when used only as a forwarder, qname-
minimization had no impact on how Unbound works. That's what I
understood, reading this presentation
https://www.nlnetlabs.nl/downloads/presentations/unbound_qnamemin_oarc24.pdf
(page 22).

Kind regards,
sohka