Nearly all LiIon charger will reduce current when the battery i nearly full, I would give it a bad review if it did not. This can be seen on the curves in all my reviews.
The display may not show the actual current, but the selected current.
Yes, right, but as you say the display do not show any reduction of current. So the Mixboxer is the more honest charger on the market! 
But often it does not respect the manually selected current also when the battery is charged at just 10% if the IR is high. Why does the hell it not let me decide? When I will need a behavior very respectful of batteries I will select the Automatic Mode.
I was just reading that charging the last 10%-20% or so of lithiums at higher amps can cause "bad things to happen". This can be interpreted many ways, but for me it suggest the battery may flame out or blow. Maybe they override our impulse to charge faster near the end purely for safety reasons only, which would be a good thing.
If you were to charge at high current toward the end of the charge cycle, you would be exceeding safe voltage levels. There is a reason why smart chargers use CC/CV charging algorithm for Li-Ion cells.
Received mine today, and as expected after using the 2-bay model for a few weeks, I’m very happy with it. I put the 30Q’s from my BLF Q8 inside, and it started charging the cells that were eighty-something % full with 2.65A.
All four batteries made good contact with the sliders - can’t remember the exact IR, but it was somewhere in the thirties. I actually found that they slid into place perfectly, unlike most chargers that I’ve tried, where I often have to move the batteries about to get them in the best position.
The build quality seems really good, as well. I wasn’t quite expecting such a brick for the power supply, but I guess it makes sense if it needs 5A from a 12V connection.
The only thing that I’d like would be a clearly visible indicator that the charging process is complete - hopefully that is something Miboxer will add to future versions.
Received mine hours ago today as well. The fast charging and possibility of charging four 26650s got me.
One problem though, I have a couple of older 26650 flat top Liitokala’s I was hoping to test out, but they won’t charge at all. The charger won’t recognize the batteries.
It recognizes my 18650s fine (a NCR18650B and some 35Es), but will do nothing with the 26650s.
Can someone help me out?
Ooh, I was thinking about doing that but didn’t want to break anything. How’d you manage to do that? Pliers?
Yeah, you’re right, I just squeezed my finger between the bottom of the charger and negative tab and it does bend toward the battery and when it makes contact, charging does work.
I used pliers and held the base down with the square end of a 1/4" socket extension bar. It bends fairly easy.
I have exactly the same INR26650-50A cyan (although mine doesn’t indicate “Liitokala).
The INR26650-50A contacts does not touch the charger’s slider + or - contacts, you’ll need to carefully adjust the INR26650-50A at a slight angle until it touches the charger (forgot if it’s slanted towards the front or back, but try them).
Dunno if it’s too safe or not, but I took what klrman said about the wrapping blocking contact and just shaved off the wrapping on the negative side of the battery. Worked like a charm.