I would assume not much, it's an incursion. Meaning they don't have the infrastructure to ship it back. If they find any caches, they probably would take what they can use quickly, and destroy the rest.
That all makes sense. I saw today they have captured at least one tank which is nice.
They've penetrated two prepared defence lines which they may want to hunker down in later so shipping ammo back to those would be less hassle.
There's some talk of them potentially holding that gas plant to force Russia to destroy it to dislodge them too, cutting off gas to Hungary while making Russia the one that does it. Muuuaahahaha.
The whole thing is fascinating. Really looking forward to the Perun video on it which will hopefully be next week.
Of course the narrative will be 'Ukraine forced our hand.' but everyone, of course, will know better.
Actually, I hadn't thought about that aspect of the incursion. They can potentially disrupt a large amount facilities that give them the remaining export abilities they still have.