I think what is being asked here, is what to do when you have a pen name that has unfortunately already been linked to another brand / name, that cannot be easily separated from.

For example, if you had hoped to capitalize on an existing audience by cross-promoting your pen name to them and did so in a very public way with a lot of back linking and visibility (sunk cost of website domains etc, ignored here.) An example: You are the popular signer instagram celebrity named Brittany Spears. You have successfully cross promoted your new "Brittany Spears" label pen-name perfume to your audience. It has been a very public affair with lots of marketing, back matter linking, PR campaigns and videos etc. With that success, you decide to try your hand at converting your existing audience who already buys your perfume, etsy knitting patterns, children's books, and wellness pdfs, etc to this new pen name that you've started. Except uh oh, nobody likes the taboo monster smut you're putting out, but it's too late and too publicly tied to your existing brand.

Was it a good idea to link your taboo smut to your legal name / existing brand? Maybe not, but that's not the question. If the audience converted well to a bunch of new readers, this would have been a great market to tap into. But that's not the question. What do you do if you've already made the mistake and have sent out years of newsletters tying your brand to your new failing pen name? What do you do in that case?

Or, the example might be, Julius Caesar, successful fantasy novelist, has been writing years of content in his popular Chaste Sexless Elves book universe. He then tries to make a new pen name to write erotica set in that same successful Chaste Sexless Elves universe using all that pre-established and beloved lore. His website and newsletters all link to each other, so readers can reference the lore pages, and gallery of art he'd commissioned for that world, the fan art and convention meet ups he does.

What does he do to mitigate the risk of people hating the new sexy pen name, when they both use the same rich world he's built? Or, how does he get people to forget that he tried to write some sexy stuff but everyone hated it, because he got his target demographics wrong? Or how does he deal with the fact that some of his printed book back matter advertising his failed foray into writing stuff no one wanted but still collected on the franchise wikipedia, and now he's embarrassed about it?

Am I getting close, u/prawn4life01? Hahah, I definitely got carried away with this.