There is really no reason to believe jws are easier “targets” via the Witnessing carts. They’ve had a public ministry for decades (instead in manning a cart, they’d simply walk the public streets and approach people). Don’t think this makes encounters more frequent, personally, because there is risk associated with that as well — if an apostate doesn’t end the conversation after being asked, he can be guilty of harrssment.
And me personally, actually enjoyed when ex-members tried to plant seeds of doubt. They outed themselves by the type of questions they asked.
But nowadays, when someone asks me about child abuse issues in the ministry, I test their sincerity and say “can I research this and get back to you”? The two times I used that question, the person said “no thank you”. Probably an apostate.
So it’s actually easier to neutralize them. Ask to schedule a follow up. Most, if not all, “apostates” will immediately decline, thus, outing themselves.
Asking Jws about the GB being “leaders” is a red flag anyway. The type of question being asked most times tells you about the person asking it. So really, you can’t fool us that way.