How can we override a behaviours property?

[breningham]

We are currently using NextJS as a microsite, currently having 2 seperate microsites in nextjs (using the sls-next-cdk stack to deploy it ) with a gatsby main site, using cloudfront behaviours to glue everything together (for now).

currently we are getting CORS errors for static css files. and i cannot find a way to override the static's behaviour to add the relevant responseHeadersPolicy without overriding the entire behaviour.( which i cannot do as we cannot get the s3 bucket before its created. )

Any ideas?