We are targeting corporate and I would suggest that you get to understand Amazon Web Services as this is ultimately where your customer’s app sits. The security and scalability is determined by the infrastructure offered by AWS and Bubble.is is simply the platform / language you have chosen to build the app in.
Corporate are interested in where the data is stored if it’s in a silo or shared app - bubble.is offers both with a dedicated option. Bubble uses RDS and PostgresSQL encrypted at rest https://aws.amazon.com/rds/postgresql/ I also assume they have some form of load balancing for the shared app so would check out https://aws.amazon.com/elasticloadbalancing/ but on dedicated would use AWS EC2 server and s3 at AWS for file storage.
The up shot is don’t get hung up on the Bubble.is platform, see it as the container / language used for your app rather than the app and that container can be moved anywhere in the AWS cloud. You may have to list Bubble.is as a processor but using any of the AWS services and infrastructure is what is important.