I don’t think the Interdict of Merlin applies to instructions given by Harry to Hermione about Patronus 2.0. First, I’m not sure Patronus 2.0 would be considered powerful enough to fall under the Interdict. Then, it’s not really instructions to cast the spell that Harry is giving—the formula of the spell itself, “Expecto Patronum” isn’t included. And finally, Harry didn’t write full instructions, but a puzzle that would help Hermione solve the problem herself, like Harry did.
I don’t think the Interdict of Merlin applies to instructions given by Harry to Hermione about Patronus 2.0. First, I’m not sure Patronus 2.0 would be considered powerful enough to fall under the Interdict. Then, it’s not really instructions to cast the spell that Harry is giving—the formula of the spell itself, “Expecto Patronum” isn’t included. And finally, Harry didn’t write full instructions, but a puzzle that would help Hermione solve the problem herself, like Harry did.