Well, the optics I have, per se, don’t fit!
However, if you use some holders below the optic, it may be possible. But only the FW1A Bezel. With the FW3A bezel the optics (even some smaller ones) don’t fit.
The optics - at least the ones I have - are smaller in diameter and, specially in height, than the reflector. So, to make them fit by their own, we’d need to add some extra lenses above.
Or, depending on the type of holder, it may fit with some mods.
See the black holder (this is an old photo)? That one matches the height of the FW1A reflector, but it is larger, so it needs to be filed in diameter to fit into the bezel.
Also, one needs to be careful when using these holders and optics due to 2 things:
a) the beam that it will produce, specially it if it is a narrow beam optic and XPL-HI Led
b) the possibility to inadvertently rotate the holder/optic and damage the LED, either it has a dome or not.
A “pebbled” (hive) optic or a “frosted” optic will produce a very wide beam, no hotspot, and homogeneous beam. A 25º or 45º optic…may produce a horrible beam.
Check this hold thread where I made some experiences with different optics and the same led type I have in my FW1A (XPL HI).
Hope this helps!!