The reviews over on badmintonCN have been pretty good.
https://www.badmintoncn.com/eqm.php?a=view&eid=13270&mag_hide_progress=1
The Saga 2 Pro are my main pair right now.
As far as I know these are the same shoes but with traditional laces compared to the BOA-system on the Saga 2 Max.
Had some knee pain with my previous pair but it diapperead after switching to these shoes.
While the cushioning is top notch you have to keep in mind that these are pretty heavy and your feet are a bit more elevated so you don't have the best court feel compared to most other badminton shoes.
The laces provide good lockdown, can't tell you though how good the BOA-implementation is on the Max as I didn't get to try these.
There are several Li Ning Basketballshoes and running shoes which also use the BOA-System and from what I have heard are pretty good. Would expect Li Ning to have it implemented in a similarly good way given their experience.
Only downside imo is that the traction isn't particularly great. Not saying it is bad by any means but our club plays in sports halls where you have slightly older and somewhat dusty floors. Some Victor and Yonex shoes f.e. offer better grip.
If you have floors that provide more grip or play on proper badminton mats this shouldn't concern you.
I will be on vacation in China next month, hoping to find a pair of these while I'm there (without having to pay upwards of 220€ and taxes on top of that when buyinf these online).