This is in stark contrast to anything I have ever posted here before- that might be too much light. Under water if there is any sediment, light reflects a little like it does in the fog. An intense beam becomes a blinding wall of light. Unless you have very clear water to dive, you might want to try an overdriven XML2 first.
Nice looking reflectors, check out this thread about beam shots of the XHP70. And post what you build and learn so I can follow suit.
You could ask Simon if he would sell you a Convoy L6 reflector. He’s usually very accommodating with things like that. I don’t know if it’s bigger than you’re looking for but it’s one of the only XHP70 reflectors I know of that completely eliminates the cross/dark spot in the XHP70 beam and it’s an OP reflector so it’s pretty floody.
I don’t think you will have to worry about the 5-6 hot spots being visible in the beam except within a very small distance like a foot. However you might worry about the doughnut hole. A heavy OP reflector like in the L6 gets rid of the doughnut hole. You should choose your reflectors or optics based on how large you want your beam. Small diameter reflectors make large beams and large reflectors make small beams. Places like Kaidomain have a large selection of reflectors. Find one with a heavy OP finish and an emitter hole size large enough to fit the XHP70, around 10mm.
Here is how to do a quick estimate of your beam size. The focal length of a reflector is the distance from the emitter to the reflector surface. A reflector, then, does not have a single focal length, but has a range of focal lengths. A quick approximation for this purpose is just to say the focal length is the reflector radius, r. Then the beam size at some distance, D, will be (D/r)(emitter size). A domed XHP70 has an emitter about 6mm across. For example, if you have a 20mm diameter reflector (10mm radius), the beam size at 50m will be 30m across.