Question Randy.
How hard is it to find the microswitch buttons with the little tension bar instead of the physical spring, that can be taken apart and tuned up for better action?
the zippyy sticks have a wickedly crappy switch that has a spring and no lower contact point.
the x-arcade stick has switches that say x-gaming and they seem to be very good quality allowing tuning by adjusting the contact points which reduces the trigger pressure and makes it happen a millimeter or two sooner.
A couple of things; a coil spring in a microswitch isn't inferior. It's actually superior to a bent piece of flat metal. Both serve the same function, but my experience tells me that the coil spring will outlast the other. The other quibble is that these switches do have a contact point, but it is formed, rather than a plug of metal. If you examine the interior section of the blade where the point is formed, you'll see that it has been silver plated. This is really the same as silver plating a point, so the end result isn't much different. It's just a different manufacturing process. Silver, being a precious metal, won't be thickly deposited on any low cost switch.
X-gaming switches are usually regarded as being low quality, even though they may have a particular trait you find desirable. That being said, X-gaming sells switches, so if they are the ones which work well for what you are trying to achieve, you already have your source

But in the context of this thread, being the best options for a Defender Joystick, I would say that no microswitch based stick falls into this category. The leaf option is vastly superior where tweaking and fast actuation is desired.
Failing that, the Versa-Micro will do what you are looking for, without the need to fiddle with switch components, and can be special ordered with the levers if required.