Greetings!
You have very aptly outlined the key points - the need for flexibility and adaptability of the platform to changing business scenarios seems to be especially critical. But all this will work properly only under the condition of reliable data security
https://www.05366.com.ua/list/517162 and secure document flow, in particular when it comes to payment histories or processing of personal accounts of clients. As an option, you can consider modern practices for implementing CSI and information protection explained in this material practically and simply - useful for those planning a large-scale digital transformation.
By the way, if you are looking for a team that will not only implement a technical solution, but also help adapt the infrastructure to your needs, you should pay attention to those who already have experience in projects for the public sector or energy. This really saves time and nerves.