But remember that since there's no formal license for aerobatics, the person who teaches you aerobatics does not have to hold an FI ticket.
Just to nitpick, this is correct
after your PPL, but before that, if you want the hours to count, then he/she
will need an FI ticket, and if the person teaching you does
not have a FI ticket, unrestricted for aeros, then you really need to know who they are and why they will be OK to show you how to go about it.