If he has not filed and served his form E in time, it is possible for you to make an application for an order that he file and serve his Form E by a certain date before the hearing. The court can attach a penal notice to the order, meaning that he will be in contempt of court if he breaches it and can be sent to prison or have his assets seized.
Although the application itself would be made without notice to him, you would have to warn him of your intention to make it- ie give him a chance to file the documents. Is he also representing himself? If he is not, you can write to his solicitor and state that if there is no Form E (or good reason for no Form E) within say 7 days, you will apply to the court. Otherwise, you need to write to him directly (make sure you keep copies of any letters and bring them to court for the hearing on the 9th).
If he is also self-represented, have you checked with the court whether he has sent something in? It may be that he sent it to the court, but not to you.
Otherwise, you can ask the court at the First Appointment on the 9th to attach a penal notice to any further order to file his Form E. The reason why it is a PITA that he has not filed anything is that this will mean that the First Appointment will be a bit of a waste of time because there is no scope for moving towards settlement if there has not been full and frank disclosure. Especially where the parties are self-represented, any court hearing is extremely useful to try to reach settlement, especially if you have a hands-on judge. You only get a total of three and the third is the final hearing.
Another option is to try to get the hearing on the 9th postponed, but that will just delay the proceedings, so I would be reluctant to recommend that. Plus it lets him off the hook in a way.
It seems that if the issue of where the children live will not be resolved until the 29th, that there would be limited scope for using the hearing on the 9th to settle anyway. Is the children hearing on the 29th a final hearing?