Implications of the Period 43 stable reflector Mike Playle has found the long-sought stable reflector in Life.  It can recover from a reflection in 43 steps, which makes all oscillators of period 43 and above possible.
What major things have been waiting on the stable reflector?
 A: Stable reflectors have been known since 1996. Playle's accomplishment is finding one that has such a short recovery time and fits in such a small bounding box.
While I expect this to lead to major improvements in many patterns based on stable reflectors, I cannot thinking of anything that has been waiting on it other than some oscillator periods as stated above (which is significant in itself).
It is probably the first stable reflector that I could seriously imagine "running" without a computer available (just because it's possible and perhaps to learn something interesting about how it works).
It begins with a glider/block collision that would turn into the honeyfarm if left alone. Starting at the step just before it perturbs the honeyfarm (it looks like a hollow octagon) there are 10 steps until the new glider is produced and another 5 steps for complete restoration of the reflector. This is well within human ability to carry out manually (e.g. with checkers) and perhaps mentally with practice. I'm not sure that is a "major thing" but it might be said to be waiting on this discovery.
Depending on how Playle found this, there may be major things waiting on the search algorithm he used. It would be interesting to apply it to other stable components such as Herschel conduits.
A: My searcher is available online: https://sourceforge.net/projects/bellman/
I've found quite a few new catalysts with it. Most of them don't do anything particularly interesting (exotic eaters are very common) but I'm sure there are a huge number of interesting reactions waiting to be found.
The available search space is enormous, and I've only just started to scratch the surface of it.
