You can use
PortUp for selectively downloading and installing updates for Windows. Select only the updates that are described/labelled as security updates.
View attachment 152103
I've been using it and it works just fine. If you want to try others, here's a
list.
And yes, set your most used WiFi networks (primarily the current network) as 'metered connection' in Settings app, so that Windows Update won't auto-search and/or auto-download updates.