I've been lurking on your threads and enjoying them hugely, Hanging. Pod is gorgeous! We adopted a 'Village Dog' from Portugal 7 years ago, and the things you're coping with are very reminiscent of what we went through with our (also gorgeous!) bonkers boy.
Village Dogs are a primitive breed, and I suspect Pods might be too? That means they're not biddable and can be quite independent. They're like giant cats in dog's bodies, lol. On some things, such as our boy's prey drive, I've just accepted that no amount of training is going to magically transform him, so I just make sure that he's never off lead unless it's in a secure fenced-in area. But he's a wonderful companion and has calmed down a LOT since we first got him.
The main thing I'd say is to remember that Pod is still a puppy despite his size. We adopted Bonkers Boy when he was around a year old (he was abandoned by his previous owners and then ended up in a shelter) and it definitely took a while for him to mature and feel settled. I'd actually forgotten how hyper and barky he was when we first got him until reading through your thread. Now he hardly ever barks and in general is quite a placid dog -- aside from his walks, he lives most of his life happily sprawled out asleep on the sofa. Do take heart; this too shall pass! I guarantee that a lot of it is just Pod's age and all the change he's gone through.
Btw, in terms of the treats, you probably gave him too much of a bounty of riches to start with (understandable!), so that things started to lose their value to him. We did the same thing with the same result. Bonkers Boy only gets a single dried rabbit's ear a day for a treat now, and I think it's probably his favourite time of day aside from his walks.😂
Hang in there, you're doing a great job.