But this explains the value of scientific meetings and poster sessions where I can just tell this random tidbit to interested people without the burden of peer review.
An interesting recent development I've observed once was a tweet describing the fact that a dye (Texas red) labels brain vasculature even when injected subcutaneously. This random fact is not in the literature but is quite helpful from a procedural perspective. I think that science twitter has a potentially super valuable role to play in reporting unexpected or otherwise difficult to publish findings.
On the other hand, data sharing protocols mean the data is going to be made available, so I think that probably addresses that issue.
The problem with pilot data is that lots of things can change in the course of running the pilot; tweaks of the experimental protocol, bug fixes to code, etc.
Instead, they demonstrate that doing something this specific way is too much of a hassle, too unreliable, or too expensive to answer a particular question in a particular context: skills, budget, timeline, resources, alternative ideas, etc.
I don't see how you could write pilot results up ("Trust me, I'm usually pretty good at these sorts of things but this didn't work well"?). Meanwhile, disentangling these factors in a rigorous, generalizable way would turn it into an entirely different project.