Yes, I have the same issue. I thought that I was the only one. It sticks only when it is not used for while, but when I turn it back and forward, it turns smoothly.

Yes don't use knife :) I opened it with gopro glass mount with its suction cup. Also if you have car phone holder on windshield, you can use it. :)

Hello guys! I checked my nfb 11. 28 and it also had jumpers FIR0 and FIR2. jumper in FIF2 was cutted shorter, because there is no place under optical-in chip I removed optical by single philips screw and now I can easily change filter settings :) will try now! :)