I use Daves mounts with the diode installed pointing out the back which makes it possible to get close enough (4-5mm) to measure the raw output, it also depends on the thermopile head used. I always want to know the raw output power of the diodes I use in order to get accurate loss information of the optical components in the beam path. I also look at the raw beam pattern to pre select diodes for a symmetrical beam profile and illumination. In some cases I even found contaminated exit windows (with the 445nm diodes) which would have been baked in if run at full power.
I'm pretty sure there may be bigger deviations to be expected what the raw divergence of the FA and SA is concerned. Like the 445nm diodes these are also Lo-Fi.
I like that adjusable diode mount you got there, that's pretty much a must with a 3.1fl lens. Where did you get that?