Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.”... Douglas Adams 1952 - 2001
As Jeremy already mentioned, most of the people that participated in that group buy for the custom dichros from Semrock that would pass 660 and reflect 635 were looking to mix 400 mw of 660 from a pair of Maxyz modules with some 635 to get more visual punch.
In fact, I'll be using my dichro to combine the light from four 660 nm diodes with the light from a pair of 640 nm diodes. So I'll have two PBS cubes "upstream" of the dichro... (One for 660 and one for 640) I'll let you know how it works out.
Adam