Is there a way to view what install options were used on k3s after the fact?

If you are running k3s on a

systemd

style system then look in the systemd service config file.

cat /etc/systemd/system/k3s.service

the line with

ExecStart

will show you the parameters being passed to the k3s executable - eg:

...
ExecStart=/usr/local/bin/k3s \
    server \
	'--disable=servicelb' \

Great, thanks!

There is also an annotation in the node that shows them