Possibility of adding more segments to an existing Asset Categories Flexfield

Hello experts,

I would like to ask you for any help or your experience.

Our customer with EBS 12.1.3, is planning to implement another new organization. They need to change the number of segments for the Assets Category Flexfield. Of course first organization is using these existing asset categories for already 2 years.

Do you have experience, is it possible to increase number of segments?

If yes, is it better during implementation? Or would it be possible to do it during upgrade from 12.1.3 to 12.2.7?

What are the implications of adding more segments to an existing Asset Categories, which are in use?

Thank you for any recommendations