FreeBSD install via Proxy?

Hi,

I've got a machine sitting in a heavily firewalled environment not allowing direct internet connections, but http/https has to run via a proxy. I've found ways to get normal user activity as well as git for source updates run via proxy, but how about a fresh installation of FreeBSD

To be specific: How can I get the installer (i.e. bootonly.iso) to run it's downloads via a proxy instead of trying to connect to the internet dirctly?

I've already tried (without success so far):

o) When the installer starts going for "shell" and in the shell opening
	export HTTP_PROXY=<proxy:port>
	export http_proxy=<proxy:port>

o) Doing [Alt]-[F4] after the installer starts which brings me to a shell and then in that shell
	export HTTP_PROXY=<proxy:port>
	export http_proxy=<proxy:port>
	and leaving that console window open while switching back to the installer using [Alt]-[F1] to continue installation

Unfortunately neither of these work, not even a combination of them; the installer always reaches out to the internet directly.

Thanks much in advance for any clue,
-ewald

PS: As for "installation", I'm talking about FreeBSD 14.0 here