Hyperkitty displays incorrect domain name

Using FILTER_VHOST, I have two domains set up and working with Mailman3 and Hyperkitty. However, because SITE_ID in /etc/mailman3/settings.py points to one of the domains, that domain name always appears on Hyperkitty pages.

The FAQ says there's a way to edit the SITE_ID used by a domain:

https://docs.mailman3.org/en/latest/faq.html#id2

But I think that's just for which SITE_ID is associated with which domain, and not for what's displayed.

I already have 'dom1.tld' and 'dom2.tld' set as the display names for each site (under Postorius/Domains/Edit or admin/Sites/Site). The issue is that Hyperkitty shows 'dom1.tld' for all Hyperkitty pages, even those in dom2.tld. Presumably this is because of the SITE_ID value in settings.py.

How to get the correct domain to appear on that domain's Hyperkitty pages?