I tried deploying this solution in my AWS account after changing the hostedUIDomainName to be unique. However the stack failed with the following error :
π The following resources failed to deploy:
Resource Name: S3Bucket (AWS::S3::Bucket)
Event Type: create
Reason: broker-20221001-hostingbucket-dev already exists
As it turns out, the bucketName in hosting/S3AndCloudfront/parameters.json also needs to be changed and I did not find this in the documentation. Let me know if I can go ahead and submit a quick document change PR for this one. I think docs here should also specify the bucket name has to be unique.