The take-off thrust bump will give you more than 24K, how much more I don’t know, I suspect it depends upon the ambient conditions. Yes the bugs will move higher up than normal, to figure given at N1 LIMIT 1/1 Field 1R.
TO-B is intended for emergency use only, eg windshear, terrain avoidance etc; so the extra thrust capability is not normally used.
Full details should be in your FCOM Vol 2 under Engines - EEC and also Flight management - FMC – Thrust Management
S&L