I suspect "next mode" memory was not intentional, but rather a sloppy design in whatever driver Astrolux switched to, such that drivers retains the last state far, far too long. I wonder if you kept track of the last mode used in the Astrolux, and tested it again hours or perhaps over a day later, if it would come on in the next mode, or finally have forgotten and come on in low.
I think you are correct and the light I use every day does have this next mode memory but works fine every morning - I'll do some tests to find out how long it takes before it resets.
The Manker claims to remember for 10 seconds, I'm OK with that.
But the Astrolux even a few minutes after turning it off will come on in the next mode which is really annoying. If you want medium mode (7 lumens) it is annoying to have it come on at 102 lumens. It makes sense that if it is on one mode and you turn it off and then on again you get the next mode - that is how changing mode works on these lights. What doesn't make sense is to use the light on one mode and turn it off again and then 5 minutes later turn it on and get the next mode - that would often not be what you wanted. The problem is worse with this light than with many others because the first mode is a very low firefly mode, people that buy the light because they like that feature might want to turn the light on to see but not be dazzled by bright light, then turning the light on again 5 minutes later they get dazzled by a much brighter light level.
Testing:
I tried 5 minutes after turning off my Astrolux - came on in the next mode.
I thought I'd see if it was 10 minutes instead of the 10 seconds it should be, forgot about it and then 35 minutes had passed (oops) turned it on and it was in the next mode!
If you are camping and in pitch blackness you want some light but not too much this might work great, but if you want to check something half an hour later this isn't the best light to use - even 7 lumens is far too much for dark adapted vision!
Edit 1: 4 Hours - Astrolux HAD reset and came on low, I'll try 2 hours and see what happens.
Edit 2: 2 Hours - Astrolux went to next mode.
So far it takes longer than 2 hours but less than 4 hours to go to firefly mode instead of the next mode after whatever you last used.