Accessing BLS12-381 curve parameters

[secure12]

In the readme, it is stated that every curve has a CURVE object that specifies the curve parameters. But it seems like it is not the case for bls12-381. Should the CURVE object be exposed?

I am looking to call hash_to_field with my own DST, but keep the other parameters in htfDefaults fixed.

Update: the CURVE objects are actually in bls12_381.G1 and bls12_381.G2. However, the typings are not correct so that they are not visible.

Update: In fact, for my usage, I'll need htfDefaults, which is not available in the CURVE object either...