We are working on enhancing our approval functionalities.
We now support a number of different options for branching. Today we also added Switch case which makes it easy to have several parallel branches: https://flow.microsoft.com/en-us/blog/search-by-service/
The new modern approvals support this: hhttps://flow.microsoft.com/blog/introducing-modern-approvals/
Thanks for the suggestion, this is a good idea.