120 ft/min is min target in SRS only.
in CLB/OP CLB there is an energy trade-off between rate of change of kinetic (acceleration) and potential (climb rate) energy. But hard to put numbers on it. I recall something as 80/20, later revised to 60/40 or vice-versa even. Anyhow, the units of measure make for difficult one-to-one comparison. In the worst case the aircraft will fly level, any possible speed decay at that point (engine fail, windshear, temperature inversion) can always be counteracted with TOGA. (Which will give SRS with flap lever out of zero). Or cancelling the de-rate (D-CLB x)
In practical terms you could see this on the A330 with D-CLB 2 (reduced climb thrust) on a very hot day in the ME while turning. I have seen the aircraft flying level with only very little acceleration, easily solved by instantly cancelling the reduced climb thrust (a/thr disconnect).