ATSF SD45u and B unit horns

I have a quick question, was the ATSF SD45u and B unit pack supposed to use an existing hornsound (a built-in Leslie SS3L, second variant) or a custom three-part hornsound? The BN SD45s and I know at least the BN F45 have custom horns too.

as the author of the horn in question, what is "built-in" once was technically a "custom" horn.

when we sometimes pair with n3v for official dlc (which later can become built in content) at what point do the sounds stop being good enough? is it not still a leslie S3L? does every single engine need a completely unique hornsound?

I can understand the interest in 3-part horns, which we have been adding to new releases, but we will not be retroactively changing products in the store to have different "custom" horns.

Thank you Ryan. I understand and respect the choice to not change the horn sounds on existing models in the store.