The sst40 is not made in a domeless version. It’s too expensive and complicated for the manufacturer to try and slice the domes off individually by hand.
Or do you mean they should have used an emitter like the xpl-hi?
Here is djozz’s test of the sst-40 with an xpl.
You can see the sst40 can be brighter at higher amperage. An xpl-hi will automatically be 200-300 lumen less than the xpl. So it seems Astrolux wanted a high lumen light as opposed to a maximum distance light.
There might be other advantages to the sst40 as well. Like I said I’m not very familiar with this led. Perhaps it has a nicer-looking tint or is maybe cheaper than the xpl-hi. IDK.
I’ve only read the last half of this thread so maybe this has already been mentioned before?