If it's lossless, it may change the cut position to enable lossless. If you want cut at an exact place, then all apps need to re-encode which will never be lossless.

For your particular requirement, you can't get lossless quality all the time by any software.

LosslessCut gives you the option to cut at the nearest keyframe, or to re-encode the small portion from the chosen timestamp to the next key frame (at most a few seconds). Sounds lossless enough to me.