Hi, Yaz!
I have two of those bad boys laying around for years now (possible I even bought them from you!), but have shy'd away from using them due to lack of time, money to invest in the board I really want (a 3 level GDuP), and last, but definitely not least, the inability for that setup to use as a twisty.
Unfortunately, there are no GOOD tailcap options for the Minimag that don't introduce a bunch of brightness and efficiency loss through voltage drop (by way of contact pressure and surface area). The Terralux reverse clicky may be the only "acceptable" solution, but is crude, ugly, and still lossy. If it weren't for that problem, I'd have used those excellent heatsinks a long time ago in some kind of high power mod. Not ready to sell them quite yet... see last paragraph.
Download's offering is, by far, the easiest way to go. Twisty with no clicky resistance, and relatively easy drain on primaries.
A long time ago, I made a few attempts at improving the Kroll switch, then trying to stuff a severely shaved down 10A Judco into a Kroll. Part of which I made a thread about. None of it ended in success... haha. I've recently re-visited the thought, and may look into a small FET switch type of thing inspired by others here in the past, working on other platforms. Hopefully I can explore that sometime this year, and get a working prototype by next year to support a fully high quality high power Minimag from top to bottom. THEN I would use my mariposaoyako style sinks in anger!!... lol.