TC on the 899/959 doesn’t allow for lean, so you can’t use it the same as the 1299S. All I found it does (funnily enough also at a wet Silverstone) is cut traction which sat the bike up. As others have said, if it isn’t coming on, don’t worry about it. I don’t notice it until I look back at videos of laps. It tends to flicker a bit coming out of some corners, but you tend not to feel anything.
You can see mine flashing up about 40s into this clip at Donnington. First lap on cold road tyres in setting 3. It isn’t as obvious a light as the Rev limit, and you should be looking up the track away from it at the times it is likely to flash. Once the tyres are warm I don’t think you see it again.
