I know nothing about Zafiras other than they have a tendency to self combust. Equally I have never fitted a DMF, but I do know what they are designed to do which is to dampen any violent variation in torque or engine revolutions. There are several external factors which can cause a DMF to fail all of which introduce an extra vibration for it to absorb. One could argue that blipping the throttle during a gear change is making the DMF worker harder than not doing so. Equally one could argue that an obstructive and baulking gearbox is having the same effect upon the DMF. One will have a clockwise moment, the other an anticlockwise moment of force upon the DMF. Certainly the double declutch upchange if timed correctly should give the thing an easier life.
What to do as always depends upon your intentions regarding how long to keep the vehicle. If you are intending to keep the vehicle you should ask why it has failed. There are some aspects of driving style or the type of actual driving conditions which will be relevant, but equally an engine with a slight misfire, deteriorated Crankshaft damper, soggy engine mountings, or transmission vibrations could all have been responsible. Unless you are outing it immediately do not skimp on parts quality. That doesn’t mean that dealer parts are essential, it just means stick to well known brands, Valeo being one for clutches (and also a solid flywheel conversion kit for that matter) and LUK another for the DMF. You will need to research the wisdom of fitting a solid flywheel KIT to a Zafira should it appeal for cost.