I never had Tyga chambers on any of my NSRs to have opinion for their quality,but í have heard good things for them and looks nice.
But if i remember right,Tyga before some years had different types of chambers for MC21 and MC28 but now sells only a universal type for both.
Maybe this is the reason that they need modifications,as they are not specific for a model only.
The stock pipes have the most perfect fit,but they weigh like a boat
and if you have the stock MC28 they are restricted with a big welded washer at the front area which bolts on the cylinders.
If you cut this washers you will find some ponnies.
For your problem i believe that some other MC28 owners with Tyga chambers must reply with their experiences.
I believe that we have many of these owners in this forum
I sadly only can help for JHA on MC28 and Dogfights on other models.
Cheers
Stefanos