Do Octopus variables override values in .config transform files?

We’re using Octopus 2.4.7.85

We have a web config transform file for our environment that sets the values of some feature flags.

Is it possible to set variable values in the Octopus UI so that I can override a value that transform file would set?

I.e.

the Thing.Release.config file has

<add key="FeatureFlags.NewThing" value="false" xdt:Transform="Insert"/>

to ensure that the prod environment doesn’t have NewThing turned on. But that means I have to commit a change to source control and push that all the way through CI to get the feature switched on when it should go live.

I’d like to go into Octopus variables for the application and set FeatureFlags.NewThing to true and run a new release of that version of the application. Would that work?

This documentation page makes it look like I’d need to change the .config file to

<add key="FeatureFlags.NewThing" value="#{some_octo_variable}" xdt:Transform="Insert"/>

yep, that worked