Especially since it was a refactoring, it's generally better to handle those in stages if you're working with a team.
There are lot of ways/patterns for solving the same problem... but tearing apart an existing interface being used by others isn't a good start.
The best part about abstraction is that you can modify the underpinnings to be more flexible without hurting the rest. A good step would be to create more flexible math functions underneath, like you're saying, and leave the rest alone.
Afterwards, there can be deeper conversations with the team about how they want the interfaces to communicate to provide an obvious facade but an abstract implementation.
There are lot of ways/patterns for solving the same problem... but tearing apart an existing interface being used by others isn't a good start.
The best part about abstraction is that you can modify the underpinnings to be more flexible without hurting the rest. A good step would be to create more flexible math functions underneath, like you're saying, and leave the rest alone.
Afterwards, there can be deeper conversations with the team about how they want the interfaces to communicate to provide an obvious facade but an abstract implementation.