I know, I am not sure if this thread is even discussing the original posts.

In Minnesota we have pothole season. If you hit a pothole hard enough to notice something right away, then it would have gotten fixed, usually. The lesser hits accumulate, go unnoticed. What happens is more of a slow realization that something is less than ideal. They could ride the bike for years that way. When they have another bike to compare is when they realize that it could or should be better. Most people start adjusting the adjustable things, searching for a solution. The fork will not appear bent, and even trying to measure it may not show it is bent. But, this is one thing that would make it harder to turn.

Another case is when a smaller wheel is put the front (for the weird look I suppose, it wasn't me that tried it). It really messed up the steering response and was nearly un-ride-able. Nearly the same effect but due to tilting the frame forward.

Putting more of the riders weight on the handlebars:
I would expect this to make the bike more difficult to turn. For one it increases the static restoring force which will make the steering slightly more heavy in the hands. If you just shifted forward in the seat, that heaviness would make it hard to judge the steering input. With more weight forward, the front tire now has to turn that weight too. My expectation would be that the front tire would be more likely to skid, or hop, during the more extreme events. My expectation somewhat depends on the fact they throw a great deal of sand about in the winter here, which a rider may encounter is small or large amounts.

The danger of spilling over the handlebars should be considered too. About 4 weeks ago I came around a slight bend and met 4 riders, one of who was alongside. He tried to stop suddenly to avoid hitting me. He managed to stop the bike in about a 10 feet. He came over the handlebars and did a face plant into the asphalt too. The rest of us stopped in about the same distance without such an incident. I suspect that his weight was a bit too far forward to safely handle the unexpected.

For the general reader,
because you never know how many bikes are out there with subtle bends in the their front forks from hitting things like potholes ::
Anyone who has ever hit a pothole hard, or gone down into one of the slots of a gutter grate, may want to check their steering balance, even if the front fort "looks" ok.
But, It is too hard to measure directly without serious equipment.

Much easier to find a curved line, ride down it and try to stay on the line.
Next, you borrow a friends bike and try the same thing, just to make sure it is not you that is the problem. (For the general public, those who do not have 2 bikes)
The friends bike logically should be harder to steer through this test because it is not as familiar as your own.
But, If the friends bike turns out to be easier to steer this way. then you could end up staring at your bike for long periods of time.
When you cannot stay on the line, especially if it is easy at one speed, but more difficult at slower or faster speeds, you should suspect the fork, (IMHO of course).
This is, of course, unless you have been adjusting the frame into unusual configurations, in which case you would probably want to return it to a normal configuration and
test it again, before bending anything.
Also, the general public should not be bending anything themselves unless they already know how to bend it in tiny amounts in a precise controlled manner (which generally they don't),
and know how to measure how much they have bent it.