Amazing comprehensive review, MascaratumB! Especially with multiple videos to accompany the static review page. Intriguing how Imalent generously sent a MS18 for you to review, while this model has already been out for 2 solid years. That’s quite a testament to their confidence in your review quality. And really, you did not disappoint. Kudos! 
I’m amazed that Imalent hasn’t made a slipstream version upgrade of the MS18 UI, given the price at over 400€. Frankly, given the dangerous power of this light, one would expect that a forced low control (press+hold from off) would be a given. The fact that you will get the last brightness used and it could easily be right below turbo is… not good.
Preferably, I would think that a single click from OFF should never go above the medium setting. It’s just so easy to step up from there. And there’s also turbo had by double-click from OFF.
Also, given the massive size, this flashlight should have a tripod mounting point on the body or bottom collar of the head. At least there’s a shoulder strap!