The ROP must have been a super duper thing to behold at first. 1000 lumens from a 2C maglite that ordinarily put out what, 20? 25 with new a brand new one?
The super duper ROP light did involve some modification. A custom delrin sleeve, upgraded switch and the tailcap was modified with a copper ribbon and much smaller spring to allow batteries to sink into the tailcap as two 18650's stick out beyond the body. There was also some with a spacer added between the body and tailcap to make even more room for batteries.
Here's one that turns off light sensing porch lights from 100' away.
The tailcap mod.
When the on switch is clicked you can almost hear it hum with 20amp batteries.
Before the kadomain reflectors came along you had to have the reflector custom made by folks like the Sandwich Shop. I scored this one already built for a lot less than it would cost to build. Finding Pelican Big D halogen bulbs was the hardest part. Pretty scarce these days.
I think fivemega still has some bulbs that get pretty bright though.
I didn't mention the battery sleeve because I think it's obvious. Other than that my Blue 2C ROP is just using a Pelican 3854H bulb, a Borofloat lens and metal reflector. Nothing more than that and it works great. The 3854H bulb is a 6V 25W bulb. At 6V the bulb is drawing a little over 4A. With 2x 18650 fresh from the charger it might be a little more but never so much the stock switch can't handle it.
I see you installed Download's MagRing2 kit which gives you a little more room for the cells but my Blue 2C has just a short spring in the tailcap and 2 unprotected cells fit without needing the lanyard attachment from the kit. You might get a little less resistance (= higher output) because of the copper braided strip but I can tell you even without Download's kit my ROP works great and the light is pretty bright. Back in the day metal reflectors were offered by some of our members (I got mine from litho123). The reflectors from Kaidomain with removable cam have a big hole (15mm) while the reflector in my Blue ROP as well as the Red deep reflector from Fivemega only have a small hole which fits the Pelican bulb much better.