Managed descent, altitude constraints, radar headings

[gimbal error]

And yes, I made it common practice to set the restricting MAX Altitudes on the FCU during climb out. Here's why:
VNAV climb out with numerous altitude contraints up to cruise level. All nicely set up in the FMS, double checked all the parameters, AP working in the expected mode, clean up done, zooming up towards cruise altitude, 20 seconds prior to the next altitude constraint you get that "traffic at 2 o'clock, reduce climb to 1500 Ft/min max" call from ATC. A quick push onto that VS button, both heads looking out to catch the traffic. And there goes your altittude level off. Unless you have it set on the FCU.