Don’t wait. Of course if you want you can, but more than one, two days is pointless in my opinion.
Don’t do it, always do full upgrade. Even if it’s small package it can have many dependencies – so partial update can broke system even in this situation.
If that’s Manjaro issue, it is always fixed almost instantly (I’ve never meet such bug on my systems). If this is upstream bug Manjaro have nothing to say in this situation – this kind of bugs (example) usually are fixed in next update, but not always, some bugs live longer, it depends on upstream. On the other side, a new update can introduce new bugs. You never know what the future will bring – that’s the nature and beauty of rolling release 