Real name or username

People who are present on several platforms most likely use the same username.
Simply for a practical reason.
Legality has nothing to do with it.

Just relax and do whatever you think is right. When the time comes, you'll decide whether you want to be recognized by name or by brand or your name WILL become a brand.
I think that traceability is not a problem.

If you plan to sell models only on CGTrader then by and large it does not matter but of course it is better if there is something readable and memorable and not just something like jewel123 or cgt-user34567. Cobalt-blue is quite a good name.

If the name is Pedro Morales Magonzales Marato Molaso Mondustos, Mike Oxmaul or James Smith it's not the best option for successful sales. In this case, it is better to reduce to Jeweller Oxmaul and Pedro Jewel (for example) and replace James Smith with something less popular.

thanks everyone appreciate

nic