Forty years ago, the best builder and flyer in our local club (an engineer by trade) made a simple comment. If you really want a plane to fly well, provide it with the ability to adjust the stab. Probably like most, those words didn't affect my building of kits that didn't provide such means.
In recent years having embraced plan or self design builds of giant scale, the words were remembered, perhaps because of concern of putting a lot of time and effort into projects and wanting them to fly well.
We expected a kit to fly well and the designer was trusted to have done the work. When the design is our own or we've taken liberties with a design, or want the best possible trim, then the onus for a well flying plane is on us and giving a build the means to trim it, is a reasonable - even prudent thing to do.