What is the best way to direct multiple domains to one folder?

Question

Nginx

Hello, please tell me how best to organize this work:
There is a site on wordpress multisite (a common directory for all sites /www/site1.ru, a common database for all sites)

To connect other domains to this network ( site2.ru, site3.ruetc.), you can create them as separate sites (in this case, you can conveniently get an ssl certificate for them) and either by changing the config. file, or send a symlink to a folder /www/site1.ru(I understand correctly that in this case performance suffers, does it depend on the php operation mode, will the number of running processes increase?)

Another way is to register all domains as aliases for site1.ru (and even at once you can get ssl for everyone), but here's what to do if you need to constantly add new ones (constantly regenerate this common certificate)
LetsEncrypt certificates are used and multiple domains are expected to be added.

Maybe it's better to solve this problem differently? Thank you.