Life is full of revelations. In my case, this revelation is a slow realisation of the blatantly obvious.
I’ve been fretting over the instructions for a two-wavelength Eliza. These instructions will involve soldering and flash stuff like that. It’s OK for those who solder for pleasure, and who are at one with the finer points of electrical connections, but most Eliza-makers are happy to avoid unnecessary complications.
So, applying the KISS (keep it simple, stupid), I offer this pronouncement:
Make two Elizas (or Daffodils), one with the ~670nm LED strip and the other with a longer wavelength. While 810nm is the fashionable one, it has been difficult to get, whereas 850nm is much easier to find.
Then use the two light hats in sequence, one immediately following the other. I tend to use the ~670nm first, then the longer wavelength second. I’m not sure that it makes much difference which goes first, as long as one quickly follows the other.