This was my first attempt at customization way back in 2015. Really just wanted to see what I could do with an aluminum tube. Since then my knowledge, skills and tool selection have greatly improved. The point being is that it's quite possible to make a large decorative window in a saber emitter as thick as the Aeon v3. Not easy and requires patience and tenacity.
Whoa that looks really nice.. I applaud your patience and bravery!
I think that if I ever tried to customize a saber I would go for one of the larger hilts, similar to maybe the Sentinel or Apprentices... after working in machine shops with all types of metal sometimes my saber hilts remind me of some of the huge drillbits and endmills I used to dip into all the wonderful chemicals we had, such as the cleaner and protective fluids we would dip the bits we sharpened and customized.
A small circular saw such as yours is the perfect size, I would be afraid to take out my larger Dewalt circular saw. I may grab a hilt by itself one day and experiment. I would probably go with a Stunt, nothing high end (would be too afraid to damage)... and depending on where the retention screw is just avoid it and mark where I would want to cut. I would maybe design a small stencil first out of some cardboard.
I personally am terrible compared to the guys I work with in the shop come the professionalism. But they've taught me a great amount on properly drilling whether small holes for hinge screws/anchors to the larger jack-hammer like equipment for drilling into cement.
Some small Counter-Sinks would work nice if you have a nice power drill. If you have enough space at the end of your hilt you could probably drill some small holes and then use a small countersink to safely (or as safe as possible) open up the drill hold to let more light out.. I wouldn't recommend it though... but now I'm interested.
I also love the weathering aspect, as beautiful, shiny, and perfect as all US products come I've loved some of the custom stuff I've seen and certainly want to add one to my arsenal one day... I may order a hilt later today, I'll have to take a look at what would possibly be best for me and what I think I could hack away at without destroying hehe.