I have all the required documents ready to send off with my form E at the end of the month and I have some back-up documents to support my position.
Testimonials from my son's extra lesson teachers and his sports coach. And details of property values for our overseas business.
I am inclined to submit only what is required and keep the back-up for later when (and if) challenged. Providing more than is required seems like giving ammunition to the ex wife's solicitor.
What is the best approach?

I supplied much more than was needed with my Form E. That was because (so far) ex has denied so much of my contribution; and rather than have the Case become expensive and protracted; I wanted to put forward as much information as I could - to pursuade him NOT to go to a fully contested Hearing.

The term 'amunition' in itself means there is an element of Game playing. Fine for sols who make money out of your assets; and will make more money when they start requesting for you to back up your claims....

I believe in being as up front and HONEST as possible. It puts a halt to things becomming drawn out. Also; if you prove your willingness; you're far less likely to get a Cost Order against you.

Play by what's right for you and your ex.

That makes sense and was my initial thinking but my ex wife is evasive and just wont discuss anything. I know that it is playing into the hands of the solicitors but I wondered what my ex's game plan is going to be bearing in mind she is in the weaker position but never the less wants a higher pecentage than is the generally accepted maximum share that she is en­title­d to.
It seems to me by offering the information now implies that I know that I am winging it and trying it on rather than it being a justifiable expense.

Once you're in the Court room; it is lead by the sols/barristers; and you and your wife become PAWNS in THEIR game.

If you put the info with your Form E; hopefully the judge will have had time to look at it before First Appointment. If there's stuff in your favour now; then make it work for you sooner. it could put you ahead of the game.

I'm self-repping. Ex has denied my massive contribution; I filed a huge document with my Form E (judge said he hadn't read it, he hadn't had time) However, he could see that my contribution must've been big; and turned to ex and said "Do you recognise that you owe your wife a Lump Sum"?

If I hadn't filed it; it would be me sat there; trying to blurt out what I'd done. The judge may have been p*ssed off with an additional document; but it made my position clearer.
Apart from the additonal paperwork I filed; the judge did compliment me on the presentation of my Form E.

After Form E comes filing of Questionnaire, Statement of Issues, and Chronology. If it's not on file by then, then where will you put this extra paperwork? If going to FH you can then include exhibits etc. But if it will help your case earlier: (if only to intimidate your ex about even asking) then why not now?