The software allows you to add evidence at any time you want to do so. However, we would recommend agreeing the protocols surrounding this internally within your own organisation.
Some of our clients for example, undertake self-assessment once per year and stop changes being made in-year by 'Approving' each key question input.
Therefore, rather than add evidence to a report which covered a particular period in time, you may want to house it elsewhere in insightQ. For example, as an attachment to an improvement plan activity to demonstrate the progress you've made or in Store so you can use it as an evidence source in future self-assessment reports.
Other clients see it as a rolling programme of self-assessment therefore adding at any time may be exactly the right thing to do.
If this doesn't answer your question, please do not hesitate to contact us via chat.