Can an additional amount be added to Zakat funds as a precaution when paying it?

If the wealth reaches the nisab and a year has passed over it, its zakat becomes obligatory, and there is no need to add a reserve amount. If one does so, there is no harm in it; rather, it contains an increase in goodness and benefit for the poor, and its owner will be rewarded for a supererogatory charity. It is also said that the entire amount becomes obligatory. And Allah does not waste the reward of those who do good.