How to enable private-mode on kiln?

Question

according to https://tezos.gitlab.io/user/various.html

private mode can be enabled with the arguments

tezos-node run --rpc-addr [::] --private-mode \
                               --no-bootstrap-peers \
                               --bootstrap-threshold=1 \
                               --connections 1 \
                               --peer <public-node-ip>

How to enable this in kiln?

Kiln has the file etc\kiln\args to pass command line arguments

setting KILNARGS="--kiln-node-custom-args --private-mode"

is valid syntax, but how to add the additional parameters?

eg, the following does NOT work: KILNARGS="--kiln-node-custom-args --private-mode --no-bootstrap-peers"