Potty training – two plans. Which one do you think is best?

Hi everyone, happy new year 🥰

I have a 11 weeks old, he’s with me since he’s 8 weeks and a few days old. For the back story and context: he’s a working line german shepherd from a search & rescue family. I was originally the last to pick a pup from the litter so I was originally supposed to have the last female available.

Turns out after meeting the dog handler (amazing dog handler btw), he decided to trust me with this male that he originally wanted to keep because he has a lot of capacities (very working line, strong bite for his age which scared previous buyers, very handler oriented so gotta work a lot on neutral exposure since he barked at people and dogs) but he is very sensitive which can be awesome or awful in the wrong hands. He kept the female and another male and that’s how I got my beloved puppy. He’s from a winter litter – he is used to potty inside a house.

When I got him – given his sensitivity – he could not handle more than 10s outside. I’ve worked with him and after a week and a half, he’s happily jumping around outside and doesn’t want to go home. However he will ABSOLUTELY NOT potty outside.

Nothing. Ever. Boycotting it.

It doesn’t surprise me given his nature. He’s very alert outside, always ready for action, scanning everywhere, sniffing endlessly. Before you ask, even after 9 hours of sleepy time, I take him outside and nothing. I even tried to push it to one hour after wakey time. HE HOLDS IT 😭 So I’ve got two plans. Would you mind telling me which one you think would be best?

Plan A: I bought fake green grass. The plan is teaching him to go on it in the house. Have a “go potty” command. Do it leashed on the fake grass inside. Take the fake grass, put it outside. Then slowly put him on the ground with high reward (very yummy stuff). Downside: he might take time to understand there’s no potty inside, buuuuut he already thinks it’s ok 😭 a win is a win

Plan B: wait until he is fully vaccinated and stay outside for way longer, in a parc, with water, and wait.

What’s your take?