Generate PGP keys very very fast
To generate keys faster than you are doing right now probably requires to add a faster source of random numbers to your system. You could look at the extensions available in your CPU and checking if they are enabled or not on your system.

If you are only interested in looking for collision on key ID, you'd probably proceed differently.

fingerprint = hash(public_key)
public_key = timestamp + public_key_data

Therefore:

fingerprint = hash(timestamp + public_key_data)

There's a script that manipulate only the timestamp looking for a collision.
https://github.com/micahflee/trollwot