Perhaps if you were willing to talk about your beliefs I might go on to other questions such as "Do you believe that it is possible for us to determine if a God exists?" or "Do you think it is possible to find evidence that God exists?" and "Would you be willing to listen to some reasons why I feel that there is a God?"
If so we could discuss each individual reason. Really it is comparable to having a discussion here on Hacker News. There are disagreements here on HN but as long as everyone sticks to the guidelines everyone involved can have a productive conversation. I feel that likewise it is possible to have a productive conversation about religion.
Jehovah's Witnesses do have a vetting approach of sorts when it comes to determining capability but as I'm sure you will agree vetting is an extremely hard problem to tackle both accurately and fairly.
When I was around, they did't have the wealth or intellectual sophistication to advertise themselves effectively. We had been using the same sales book for years and I wouldn't be surprised if "the reasoning book" is still around. An organization that enforces orthodoxy as thoroughly as Jehovah's Witnesses isn't exactly a breeding ground for creative and entrepreneurial spirits.
I wouldn't expect them to pivot if hard sales techniques proved to be annoying or ineffective. They used to publish their conversion statistics in the January 1st or 15th edition of The Watchtower so you could follow their growth (an anemic 1% or so per year back in the late 90s). That was a shockingly transparent move for such a close-minded organization; it probably helps increase members trust in the central organization. But it is also bad for morale to watch numbers languish.
Universal evangelism in JW congregations will never disappear. The shared experience helps separate them from the rest of the world and bind them together, much like hazing at a fraternity or combat experiences in the military.
As an unbeliever growing up in a JW household, going door to door every weekend was certainly one of the most horrific parts of my early life. I am so, so glad that is over.
My issue is that more times than not, my answer tends to be followed by a list of why I'm wrong and why I should convert. If I expressed that I'm not interested in the discussion at that time, I'm bombarded with reproach. If it happens that I'm in for some friendly debate, it becomes an issue of being told that I'm wrong because god said so... followed by more intense reproach, of course in a not so friendly way.
I'm generally not a fan of discussing religion because there are no clear cut winners and it generally becomes an issue of the more eloquent party having the upper hand. More times than not someone ends up with angry-ish feelings towards the opposing party. In any case, you're probably a diamond in a sea of carbon... You guys should make door to door preaching something a member can do after being vetted as capable of not offending the population you're trying to convert.