tl;dr If you don't use ngx_http_rewrite_module, you're fine

Honestly it's such a weird feature, if you're doing complicated redirects like this in nginx where PCRE is necessary, you should do it in your application code. And if you need speed use ngx_http_lua_module.

Your opinion is that if, for a godforsaken reason, someone needs to rewrite URLs in their web server, they should avoid PCRE (something designed for string manipulation) because it's overkill, and they should use Lua (a full programming language) instead?

Am I understanding you correctly?

We do this for 3 sub-domains of ardour.org; there's no application code involved, because we're rewriting historical URLs to their current form, and the "application" doesn't do that or need to do that or need to know about that.