Can I mix "import" with other elements?

[WoJ]

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I am a bit torn because I am asking for help but this is a general question. let me know if I should dump the whole thing.

I use several layers of import to simplify my Caddyfile. An example is below (it does not look simple at all but various hosts use bits and pieces of the import, the majority just imports lan as in the example below)

(netMatchers) {
	@internet {
		not remote_ip 192.168.10.0/24 192.168.20.0/24 172.19.0.0/16 127.0.0.0/8
	}
	@local {
		remote_ip 192.168.10.0/24 192.168.20.0/24 172.19.0.0/16 127.0.0.0/8
	}
}

(lanCore) {
	log {
	    level ERROR
		format single_field common_log
	} 
	@internet {
		not remote_ip 192.168.10.0/24 192.168.20.0/24 172.19.0.0/16
	}
	@local {
		remote_ip 192.168.10.0/24 192.168.20.0/24 172.19.0.0/16
	}
	respond @internet 200
}

(lan) {
	import lanCore
	reverse_proxy @local {args.0}
}


https://registry-ui.MY-DOMAIN {
	import lan registry-ui:80
}

It works great.

I now wanted to add one single element to https://registry-ui.MY-DOMAIN: an extra header for CORS. I tried

https://registry-ui.MY-DOMAIN {
    import lan registry-ui:80
    header Access-Control-Allow-Origin '*'
}

but the header is not added (below is the last part of curl -v https://registry-ui.MY-DOMAIN):

> GET /v2/ HTTP/2
> Host: registry.MY-DOMAIN
> User-Agent: curl/7.58.0
> Accept: */*
>
(... TLS ...)
< HTTP/2 200
< access-control-allow-methods: HEAD
< access-control-allow-methods: GET
< access-control-allow-methods: OPTIONS
< access-control-allow-methods: DELETE
< access-control-expose-headers: Docker-Content-Digest
< content-type: application/json; charset=utf-8
< date: Thu, 12 Aug 2021 13:37:21 GMT
< docker-distribution-api-version: registry/2.0
< server: Caddy
< x-content-type-options: nosniff
< content-length: 2
<
* TLSv1.3 (IN), TLS Unknown, Unknown (23):
* Connection #0 to host registry.MY-DOMAIN left intact
{}⏎

Access-Control-Allow-Origin is not here, so I was wondering: can I mix import with other configuration entries? (I prefer to ask before I butcher my configuration)

[WoJ]

@WoJ

(lan) {
	import lanCore
	reverse_proxy @local {args.0}
}

I may have answered my own question because I do already use import together with something else.

Why the headers are not sent with the answer is a mystery, though (I will probably rearchitecture the question to rather highlight that part)