I've been thinking about portability for my astro setups, and low-power goes along with that. I have a light I use for flat frames, which will cover every scope I have, from the William Optics SpaceCat to the 8-inch Newt. But I also don't mind taking sky flats with a t-shirt or a couple pieces of paper. And these don't use any power.
Here's the scenario: The sun is setting and you've already setup your gear. You're sitting around waiting for the night to arrive. What else are you going to do but spend a little time taking calibration frames, flats when it's still a bit bright out, and dark flats, dark frames, and bias frames as the twilight fades—and if any of those are needed.
That's the idea anyway.
I spent a couple minutes in TinkerCad making a Flat Frame Sleeve for the SpaceCat I can print—inside diameter is 83mm. I ordered some 3 1/2 inch diameter, 1/8in thick "White Acrylic Round" things (Link below). I glued one of the acrylic circles to one side, and placed three pieces of adhesive-backed loop-side velcro strips inside the sleeve to make it fit snuggly on the end of the SpaceCat dew shield. ("loop side" is the soft side). Gluing: I used a Q-tip to put a thin coat of E6000 glue on one side of the printed sleeve and then pressed down the acrylic disc and let it dry overnight.
I've used this sleeve with the Flats Wizard in N.I.N.A. twice and it works well. Give it a try. Let me know what you think!
RedCat 5 Flat Sleeve Model - (Shared/Public) Tinkercad: https://www.tinkercad.com/things/47bakxyG37l
20PCS White Acrylic Round Circle, White Acrylic Rounds: https://www.amazon.com/dp/B081YHZGRL
E6000 Craft Adhesive: https://www.amazon.com/dp/B007TSYNG8