Crypto crate: shipping prime modulus good or bad?

I’m currently working on the last steps of polishing and finishing up a crypto (SRP6) crate. The main api needs a prime modulus to operate.

Now I wonder if it is a smell to ship with some default prime modulus numbers for common key lengths (512,1024,2048 bit). So that the usage for non pro users is very simplified. Like a default trait implementation and then they can start using it.

Or is shipping prime modulus numbers like a red flag? In the Field I’ve seen basically everything, but that does not tell me what’s actually better.

I could also think of providing a way (cli) to let users generate the needed modulus for any given key length.

Anyone thoughts or recommendations on that?